The sodium sensor fluoresces under a UV light, moving to a more intense green as the salt levels increase.
|
|
The scientists measure which state the atom is in by whether it fluoresces (glows under an added energy source) or not.
|
|
"Green fluorescent protein doesn't really interact with anything in your cells, it just goes in there and fluoresces," he told me.
|
|
Yet, surprisingly, when the researchers injected embryos with calcium that fluoresces, they could see flickering calcium waves—the beginnings of the heartbeat.
|
|
To test whether pieces of virus they're interested in are actually in the sample, technicians add a dye that fluoresces in the presence of DNA.
|
|
To watch the calcium move in real time, Toyota and his colleagues bioengineered plants to produce a protein that fluoresces around calcium, lighting up the interiors of plants like a Christmas tree.
|
|
That is a molecule found naturally in jellyfish, but which is now widely used to tag other molecules for study since, as its name suggests, it fluoresces under the right sort of light.
|
|
Exactly where on its body an animal fluoresces might lend clues to the functional significance of its colors, though Lamb and Davis caution that much of this thinking is still just a hypothesis.
|
|
Filipe Natalio, a scientist at the Weizmann Institute of Science, and his colleagues synthesized glucose molecules that also carried a magnetic molecule or one that fluoresces into the cells that then used them to form the fibers.
|
|
"If you put the correct wavelength to it, it fluoresces, and it binds to the parts that are implicated in Alzheimer's, the beta amyloid plaque," one of the substances in the brain that is a hallmark of the condition.
|
|
Publisher: University of Nebraska Press. 1992. Dried sumac wood fluoresces under long-wave ultraviolet radiation.
|
|
It fluoresces strongly when partitioned into lipids, but practically not at all in aqueous solution.
|
|
Genuine stamps were printed on paper that fluoresces under a blacklight. Generally, forgeries do not fluoresce.
|
|
A modern parallel to ancient miners seeking luminous gems at nighttime is mineworkers using portable shortwave ultraviolet lamps to locate ores that respond with color-specific fluorescence. For instance, under short-wave UV light, scheelite, a tungsten ore, fluoresces a bright sky-blue, and willemite, a minor ore of zinc, fluoresces green (Ball 1938: 501).
|
|
A microarray chip contains complementary DNA (cDNA) to many sequences of interest. The cDNA fluoresces when it hybridises with a matching DNA fragment in the sample.
|
|
The smaller anterior spines are half to a third of that length and are oriented parallel to the larger spines. The upper surface of the abdomen fluoresces blue-green under ultraviolet light.
|
|
Europium dichloride can form yellow ammonia complexes:EuCl2•8NH3, and can dissolve to pale yellowish EuCl2•NH3. Europium dichloride can react with europium hydride at 120-bar H2, producing EuClH that fluoresces green.
|
|
Luis Alejandro Capdevielle Flores was born in Hermosillo, Mexico. He grew up in Hermosillo city with his parents; Alejandro Capdevielle, editor and journalist, and Laura Fluoresces, accountant. He graduated from law school at the Autonomous University of Mexico (UNAM).
|
|
Ninhydrin reacts with amino acids and amines to form a colored compound "Ruhemann's purple" (RP). Spraying with a zinc chloride solution forms a 1:1 complex RP:ZnCl(H2O)2, which is more readily detected as it fluoresces better than Ruhemann's purple.
|
|
Red fluorescent protein (RFP) is a fluorophore that fluoresces red-orange when excited. Several variants have been developed using directed mutagenesis. The original was isolated from Discosoma, and named DsRed. Others are now available that fluoresce orange, red, and far-red.
|
|
Abernathyite is a transparent, yellow mineral that occurs as tabular crystals up to . The mineral has a single perfect cleavage on {001}. Abernathyite fluoresces yellow-green in longwave and shortwave ultraviolet. Because of its uranium content, the mineral is radioactive.
|
|
L. clemsonensis is pathogenic; most Legionella species are commonly known to cause pneumonia. A feature that sets L. clemsonensis apart is that under ultraviolet light, it fluoresces green, which differs from other Legionella strains because they usually fluoresce blue, red, or yellow.
|
|
When present together in solid solution, energy is transferred from the higher-energy tungsten to the lower-energy molybdenum, such that fairly low levels of molybdenum are sufficient to cause a yellow emission for scheelite, instead of blue. Low-iron sphalerite (zinc sulfide), fluoresces and phosphoresces in a range of colors, influenced by the presence of various trace impurities. Crude oil (petroleum) fluoresces in a range of colors, from dull-brown for heavy oils and tars through to bright-yellowish and bluish- white for very light oils and condensates. This phenomenon is used in oil exploration drilling to identify very small amounts of oil in drill cuttings and core samples.
|
|
Jablonski diagram. After an electron absorbs a high-energy photon the system is excited electronically and vibrationally. The system relaxes vibrationally, and eventually fluoresces at a longer wavelength. The fluorescence lifetime refers to the average time the molecule stays in its excited state before emitting a photon.
|
|
Pressure-sensitive paint (PSP) is a method for measuring air pressure or local oxygen concentration, usually in aerodynamic settings. PSP is paint-like coating which fluoresces under a specific illumination wavelength in differing intensities depending on the external air pressure being applied locally to its surface.
|
|
Cubic zirconia has no cleavage and exhibits a conchoidal fracture. Because of its high hardness, it is generally considered brittle. Under shortwave UV cubic zirconia typically fluoresces a yellow, greenish yellow or "beige". Under longwave UV the effect is greatly diminished, with a whitish glow sometimes being seen.
|
|
Pure samples were subsequently obtained by handpicking huttonite grains under a microscope. This was accomplished either in the presence of short wave (2540 Å) fluorescent light, where the dull white fluorescence distinguishes it from scheelite (fluoresces blue) and zircon (fluoresces yellow), or by first boiling the impure sample in hydrochloric acid to induce an oxide surface on scheelite and permitting handpicking under visible light. Hutton suggested the huttonite contained in the beach sand and fluvio-glacial deposits originated from Otago schists or pegmatitic veins in the Southern Alps. In addition to New Zealand, huttonite has been found in granitic pegmatites of Bogatynia, Poland, where it associated with cheralite, thorogummite, and ningyoite; and in nepheline syenites of Brevik, Norway.
|
|
Strontianite is almost always fluorescent. It fluoresces bright yellowish white under shortwave, mediumwave and longwave ultraviolet radiation. If the luminescence persists after the ultraviolet source is switched off the sample is said to be phosphorescent. Most strontianite phosphoresces a strong, medium duration, yellowish white after exposure to all three wavelengths.
|
|
It has refractive index values of nω=1.523 and nε=1.529. It has one direction of perfect cleavage and exhibits conchoidal fracture. It fluoresces a bright orange. Afghanite It was discovered in 1968 in the Lapis-lazuli Mine, Sar-e-Sang, Badakhshan Province, Afghanistan and takes its name from that country.
|
|
Fuchsite crystallizes in the monoclinic crystal system. Common colour of the mineral is pale green to emerald green depending on the amount of Cr substitution. The micaceous crystals are flexible and slightly sectile with a hardness of 2-2.5 on the Mohs scale. Fuchsite fluoresces lime green under long wave UV light.
|
|
Artificial willemite was used as the basis of first-generation fluorescent tube phosphors. Doped with manganese-II, it fluoresces with a broad white emission band. Some versions had some of the zinc replaced with beryllium. In the 1940s it was largely replaced by the second-generation halophosphors based on the fluorapatite structure.
|
|
To follow the transition of dsDNA (double-stranded) to ssDNA (single-stranded), intercalating dyes are employed. These dyes show differential fluorescence emission dependent on their association with double-stranded or single-stranded DNA. SYBR Green I is a first generation dye for HRM. It fluoresces when intercalated into dsDNA and not ssDNA.
|
|
Regarding proteins, these molecules themselves will fluorescence when they absorb a specific incident light wavelength. One example of this, green fluorescent protein (GFP), fluoresces green when exposed to light in the blue to UV range. Fluorescent proteins are excellent reporter molecules that can aid in localizing proteins, observing protein binding, and quantifying gene expression.
|
|
Similar to ISR, IDA also utilizes colorimetric (C-IDA) and fluorescence (F-IDA) indicators. In an IDA assay, a receptor is incubated with the indicator. When the analyte is added to the mixture, the indicator is released to the environment. Once the indicator is released it either changes color (C-IDA) or fluoresces (F-IDA).
|
|
Methylene (systematically named methylidene and dihydridocarbon; also called carbene) is an organic compound with the chemical formula (also written ). It is a colourless gas that fluoresces in the mid-infrared range, and only persists in dilution, or as an adduct. Methylene is the simplest carbene.Roald Hoffman (2005), Molecular Orbitals of Transition Metal Complexes. Oxford.
|
|
Mercury(I) bromide or mercurous bromide is the chemical compound composed of mercury and bromine with the formula Hg2Br2. It changes color from white to yellow when heated and fluoresces a salmon color when exposed to ultraviolet light. It has applications in acousto-optical devices. A very rare mineral form is called kuzminite, Hg2(Br,Cl)2.
|
|
The hind pair of spines is always well-developed and intermediate in length between the first two pairs. Adult females are usually dark red or brown and can show pale yellowish or whitish stripes horizontally across the upper surface of the abdomen (example from Thailand). The upper surface of the abdomen fluoresces blue under ultraviolet light.
|
|
Therefore, large volume of staining solution is recommended, at least ten times the volume of the gel. Ethidium bromide (EtBr) is a popular nucleic acid stain. EtBr allows one to easily visualize DNA or RNA on a gel as EtBr fluoresces an orange color under UV light. Ethidium bromide binds nucleic acid chains through the process of Intercalation.
|
|
Crithidia luciliae is a haemoflagellate protist with an organelle known as the kinetoplast. This organelle contains a high concentration of circular DNA with no recognisable nuclear antigens, allowing for the reliable detection of anti-dsDNA antibodies. The kinetoplast fluoresces if serum contains high avidity anti- dsDNA antibodies. This test has a higher specificity than EIA because it uses unprocessed DNA.
|
|
Semen is a colorless fluid that is ejaculated from a male's penis due to sexual arousal. In order to initially detect semen, an alternative light source (ALS) is used. Under UV light, semen fluoresces making it visible to investigators to collect samples from a crime scene. A common presumptive test for detecting semen is called the acid phosphatase (AP) test.
|
|
Two samples of quinine dissolved in water with a violet laser (left) illuminating both. Typically quinine fluoresces blue, visible in the right sample. The left sample contains chloride ions which quench quinine's fluorescence, so the left sample does not fluoresce visibly (the violet light is just scattered laser light). Quenching refers to any process which decreases the fluorescence intensity of a given substance.
|
|
Platinocyanide, also known as tetracyanoplatinate (IUPAC), cyanoplatinate, or platinocyanate, is a polyatomic ion with the molecular formula [Pt(CN)4]2−. The name also applies to compounds containing this ion, which are salts of the hypothetical platinocyanic acid (sometimes platinocyanhydric acid). Barium platinocyanide, Ba[Pt(CN)4] is a phosphor and a scintillator. It fluoresces in the presence of x-rays and gamma rays.
|
|
Azotobacter produces pigments. For example, Azotobacter chroococcum forms a dark-brown water-soluble pigment melanin. This process occurs at high levels of metabolism during the fixation of nitrogen, and is thought to protect the nitrogenase system from oxygen. Other Azotobacter species produce pigments from yellow-green to purple colors, including a green pigment which fluoresces with a yellow-green light and a pigment with blue-white fluorescence.
|
|
Microsporum audouinii fluoresces when examined in ultraviolet light (Wood's lamp). The two main growth media employed to test for M. audouinii are Sabouraud's Dextrose agar and potato dextrose agar. On the former, growth is slow with and poor sporulation with most strains producing a few abortive macroconidia and sparse microconidia. The colonies are flat, dense and cottony in texture with a greyish-white to reddish brown hue.
|
|
In a related process, oxidation of a cold mixture of para-aminodimethylaniline and meta- toluylenediamine gives toluylene blue. This indamine is formed as an intermediate product and passing into the red when boiled; and also by the oxidation of dimethylparaphenylene diatnine with metatoluylene diamine. It crystallizes in orange-red needles and its alcoholic solution fluoresces strongly. It dyes silk and mordanted cotton a fine scarlet.
|
|
Traditionally, chemical sensing has been approached with a system that contains a covalently bound indicator to a receptor though a linker. Once the analyte binds, the indicator changes color or fluoresces. This technique is called the indicator-spacer-receptor approach (ISR). In contrast to ISR, Indicator-Displacement Assay (IDA) utilizes a non-covalent interaction between a receptor (the host), indicator, and an analyte (the guest).
|
|
Tugtupite is tenebrescent, sharing much of its crystal structure with sodalite, and the two minerals are occasionally found together in the same sample. Tugtupite occurs as vitreous, transparent to translucent masses of tetragonal crystals and is commonly found in white, pink, to crimson, and even blue and green. It has a Mohs hardness of 4 and a specific gravity of 2.36. It fluoresces crimson under ultraviolet radiation.
|
|
The cells have peritrichous flagella which enable motility. The species also produces a diffusible yellow-green or red-violet pigment which fluoresces bluish-white under ultraviolet light. A. agilis was first isolated and described by Martinus Beijerinck in 1901, who obtained the species from Dutch canal water in Delft. Beijernick's original strain has been lost, so the strain isolated by Albert Kluyver and van den Bout is now the neotype.
|
|
Under ultraviolet light, the quinine in tonic water fluoresces. Tonic water (or Indian tonic water) is a carbonated soft drink in which quinine is dissolved. Originally used as a prophylactic against malaria, tonic water usually now has a significantly lower quinine content and is consumed for its distinctive bitter flavor, though it is nowadays also often sweetened. It is often used in mixed drinks, particularly in gin and tonic.
|
|
When placed under blue light, the marked areas exhibit fluorescence. :- Visible Implant Elastomer (VIE): Colored fluorescent elastomer material is injected into tissue with a hypodermic syringe. The material then cures into a pliable, solid well-defined mark, which fluoresces under blue light. :- Passive Integrated Transponder (PIT): Small microchips (about the size of a grain of rice) that are injected with a hypodermic syringe and read with a hand-held scanner.
|
|
Umbelliferone absorbs strongly at 300, 305 and 325 nm, with log ε values of 3.9, 3.95 and 4.15 respectively, and it fluoresces blue in both ultraviolet and visible light. The powerful absorption at three different wavelengths, coupled with the fact that the energy is dissipated safely as visible light, make umbelliferone a useful sunscreen agent. The absorption changes in alkaline solution, since the phenolic hydroxyl group is deprotonated (pKa = 7.7).
|
|
Tetracycline is a broad spectrum antibiotic, and its derivative minocycline is common in the treatment of acne. The drug is able to chelate calcium ions and is incorporated into teeth, cartilage and bone. Ingestion during the years of tooth development causes a yellow-green discoloration of dentin, which is visible through the enamel and fluorescent under ultraviolet light. Later, the tetracycline oxidizes and the staining becomes more brown and no longer fluoresces under UV light.
|
|
Various crystals were mined as a valuable by-product of lead mining, including the decorative colored fluorspar (fluorite), for which no industrial use was known until the late 19th century. Fluorite is not a gem, but fine specimens are appreciated by collectors. The Weardale fluorspar fluoresces due to europium impurities under excitation with bluish-ultraviolet light. The characteristic fluorescence of fluorite samples from this area resulted in the term describing this phenomenon.
|
|
Alexandrov et al. (2008) published a variation on the thermofluor assay where SYPRO Orange was replaced by N-[4-(7-diethylamino-4-methyl-3-coumarinyl)phenyl]maleimide (CPM), a compound that only fluoresces after reacting with a nucleophile. CPM has a high preference for thiols over other typical biological nucleophiles and therefore will react with cysteine side chains before others. Cysteines are typically buried in the interior of a folded protein as they are hydrophobic.
|
|
Autunite (hydrated calcium uranyl phosphate), with formula Ca(UO2)2(PO4)2·10–12H2O, is a yellow-greenish fluorescent phosphate mineral with a hardness of 2–. Autunite crystallizes in the orthorhombic system and often occurs as tabular square crystals, commonly in small crusts or in fan- like masses. Due to the moderate uranium content of 48.27% it is radioactive and also used as uranium ore. Autunite fluoresces bright green to lime green under UV light.
|
|
Phosphor bands were introduced on British stamps from 1959 as a replacement for the previous graphite lined stamps as an aid in the mechanical sorting of mail. The phosphor is applied in vertical bands, or more recently, all over the stamp, and fluoresces under ultra-violet light. This enables the mail sorting machine to face the mail and sort it into types. Phosphor is now widely used on stamps around the world.
|
|
AGEs are biochemicals formed continuously under normal circumstances, but more rapidly under a variety of stresses, especially oxidative stress and hyperglycemia. They serve as markers of stress and act as toxins themselves. Pentosidine is typical of the class, except that it fluoresces, which allows it to be seen and measured easily. Because it is well characterized, it is often studied to provide new insight into the biochemistry of AGE compounds in general.
|
|
50px Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. A sample of herring sperm stained with SYBR green in a cuvette illuminated by blue light in an epifluorescence microscope. The SYBR green in the sample binds to the herring sperm DNA and, once bound, fluoresces giving off green light when illuminated by blue light. In order for a sample to be suitable for fluorescence microscopy it must be fluorescent.
|
|
In so doing, the phosphor is excited by the electrical energy and fluoresces producing visible light. Like plasma globes, crackle tubes respond to touch; the filaments appear to be "attracted" toward the point of contact and usually become more luminous (brighter) as the electricity is grounded. The tubes are also filled with a noble gas like neon, argon, or xenon which acts as the electron transfer medium of the cavity. The gas is typically below atmospheric pressure.
|
|
Microfluorimetry is building upon the established method of fluorimetric measurement. Using a dye that fluoresces in the presence of a target compound, fluorimetry can detect the presence of the compound by determining the presence and intensity of fluorescence. Differences in the intensity can be used to determine concentration of the compound. Additionally, if the dye undergoes a spectral shift then you can determine the absolute concentration of the target regardless of knowledge of the concentration of the dye.
|
|
Blood is composed of liquid plasma and serum with solid components consisting of red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). To detect blood at a crime scene an array of tests can be used. The most publicized test by crime shows is the Luminol process in which a chemical is sprayed onto a surface where blood is suspected to be. The chemical reacts with traces of blood, and fluoresces under UV light.
|
|
DiOC6 (3,3′-dihexyloxacarbocyanine iodide) is a fluorescent dye used for the staining of a cell's endoplasmic reticulum, vesicle membranes and mitochondria. Binding to these structures occurs via the dye's hydrophilic groups. DiOC6 can be used to label living cells, however they are quickly damaged due to the dye's extreme phototoxicity, so cells stained with this dye can only be exposed to light for short periods of time. When exposed to blue light, the dye fluoresces green.
|
|
In the case of ozone the method is known as ozone tagging velocimetry or OTV. OTV has been developed and tested in many room air temperature applications with very accurate test results. OTV consists of an initial "write" step, where a 193-nm pulsed excimer laser creates ozone grid lines via oxygen (O2) UV absorption, and a subsequent "read" step, where a 248-nm excimer laser photodissociates the formed O3 and fluoresces the vibrationally excited O2 product thus revealing the grid lines' displacement.
|
|
Thulium has been used in high-temperature superconductors similarly to yttrium. Thulium potentially has use in ferrites, ceramic magnetic materials that are used in microwave equipment. Thulium is also similar to scandium in that it is used in arc lighting for its unusual spectrum, in this case, its green emission lines, which are not covered by other elements. Because thulium fluoresces with a blue color when exposed to ultraviolet light, thulium is put into euro banknotes as a measure against counterfeiting.
|
|
He has also investigated the antiviral properties of viperin, a naturally occurring enzyme that is produced in humans and mammals. Cameron developed a microfluidic device that allowed him to simultaneously monitor thousands of cells infected with viruses. His research group infected cells in the device with a modified form of the poliovirus that produced a green fluorescent protein. The modified virus fluoresces when it is replicating, allowing researchers to monitor the replication of viruses in thousands of cells at a time.
|
|
RiboGreen is a proprietary fluorescent dye that is used in the detection and quantification of nucleic acids, including both RNA and DNA. It is synthesized and marketed by Molecular Probes/Invitrogen (a division of Life Technologies, now part of Thermo Fisher Scientific) of Eugene, Oregon, United States. In its free form, RiboGreen exhibits little fluorescence and possesses a negligible absorbance signature. When bound to nucleic acids, the dye fluoresces with an intensity that, according to the manufacturer, is several orders of magnitude greater than the unbound form.
|
|
While most marine bioluminescence is green to blue, some deep sea barbeled dragonfishes in the genera Aristostomias, Pachystomias and Malacosteus emit a red glow. This adaptation allows the fish to see red- pigmented prey, which are normally absent from the deep ocean environment where red light has been filtered out by the water column. The black dragonfish (also called the northern stoplight loosejaw) Malacosteus niger is probably the only fish to produce a red glow. Its eyes, however, are insensitive to this wavelength; it has an additional retinal pigment which fluoresces blue-green when illuminated.
|
|
Conjugating TNP to ATP renders this nucleotide triphosphate fluorescent and colored whilst allowing it to retain its biological activity. TNP-ATP is thus a fluorescent analog of ATP. This conjugation is very useful in providing information about interactions between ATP and an ATP-binding protein because TNP-ATP interacts with proteins and enzymes as a substitute for its parent nucleotide, and has a strong binding affinity for most systems that require ATP. TNP is excited at a wavelength of 408 and 470 nm, and fluoresces in the 530–560 nm range.
|
|
The scintillator consists of a transparent crystal, usually a phosphor, plastic (usually containing anthracene) or organic liquid (see liquid scintillation counting) that fluoresces when struck by ionizing radiation. Cesium iodide (CsI) in crystalline form is used as the scintillator for the detection of protons and alpha particles. Sodium iodide (NaI) containing a small amount of thallium is used as a scintillator for the detection of gamma waves and zinc sulfide (ZnS) is widely used as a detector of alpha particles. Zinc sulfide is the material Rutherford used to perform his scattering experiment.
|
|
In real-time PCR with dsDNA dyes the reaction is prepared as usual, with the addition of fluorescent dsDNA dye. Then the reaction is run in a real-time PCR instrument, and after each cycle, the intensity of fluorescence is measured with a detector; the dye only fluoresces when bound to the dsDNA (i.e., the PCR product). This method has the advantage of only needing a pair of primers to carry out the amplification, which keeps costs down; multiple target sequences can be monitored in a tube by using different types of dyes.
|
|
However, offspring that only get one copy of one balancer chromosome and one copy of a wild type or mutant chromosome will live to pass on its genes. After only a few generations the population will be entirely heterozygous so that its genotype can be guaranteed on at least those two chromosomes. Balancer chromosomes also come with some sort of physical marker. This marker can be actually associated with the DNA in the chromosome such as the Green Fluorescent Protein that fluoresces in ultraviolet light, or it can be an easily distinguishable physical characteristic.
|
|
An allele-specific oligonucleotide is then added in the presence of a molecule that fluoresces when bound to double-stranded DNA. The intensity is then measured as temperature is increased until the melting temperature (Tm) can be determined. A SNP will result in a lower than expected Tm. Because DASH genotyping is measuring a quantifiable change in Tm, it is capable of measuring all types of mutations, not just SNPs. Other benefits of DASH include its ability to work with label free probes and its simple design and performance conditions.
|
|
Alba was the name of a genetically modified "glowing" rabbit created as an artistic work by contemporary artist Eduardo Kac, produced in collaboration with French geneticist Louis-Marie Houdebine. Houdebine used the GFP gene found in the jellyfish, Aequorea victoria, that fluoresces green when exposed to blue light. This is a protein used in many standard biological experiments involving fluorescence. When Alba was exposed to such light, she would literally glow green — though photos by Kac showing the entire organism, including its hair, glowing a uniform green have had their veracity challenged.
|
|
DMF. Bulk powder is dark purple. Texas Red or sulforhodamine 101 acid chloride is a red fluorescent dye, used in histology for staining cell specimens, for sorting cells with fluorescent-activated cell sorting machines, in fluorescence microscopy applications, and in immunohistochemistry.Sulforhodamine 101 acid chloride Sigma-Aldrich product information Texas Red fluoresces at about 615 nm, and the peak of its absorption spectrum is at 589 nm. The powder is dark purple. Solutions can be excited by a dye laser tuned to 595-605 nm, or less efficiently a krypton laser at 567 nm.
|
|
The gel with UV illumination: DNA stained with ethidium bromide appears as glowing orange bands. DNA as well as RNA are normally visualized by staining with ethidium bromide, which intercalates into the major grooves of the DNA and fluoresces under UV light. The intercalation depends on the concentration of DNA and thus, a band with high intensity will indicate a higher amount of DNA compared to a band of less intensity. The ethidium bromide may be added to the agarose solution before it gels, or the DNA gel may be stained later after electrophoresis.
|
|
Marsh, C.W. and Liversidge, A. (1892) "On Native Copper Iodide (Marshite) and other Minerals from Broken Hill, N.S. Wales", Journal and Proceedings of the Royal Society of New South Wales, 26: 326–332. One of marshite’s distinguishing features is that prior to exposure to air the mineral is a faint honey-yellow color, once exposed to the air however it becomes a brick-red color. Another characteristic useful in identifying marshite is the dark red color it fluoresces under short-wave (SW) and long- wave (LW) ultraviolet light.
|
|
LifeAct-TagGFP2 being the most widely used dye compared to other LifeAct constructs is composed of the first 17 amino acid from the Saccharomyces cerevisiae Abp140, an actin-binding protein. The Abp140 is highly conserved among Saccharomyces cerevisiae and other closely related organisms. It is introduced as a dye but is actually a localisation marker for actin. The 17 amino acid fragment of Abp140 was genetically fused to GFP and fluoresces green when it binds the F-actin structures of living and fixed cells, allowing for visualization of cell mechanics under microscopes.
|
|
Since the 2000s, the clothing style of the rave culture remains heterogeneous, as do its followers. Particularly in North America, rave fashion continues to be characterised by colourful clothing and accessories, most notably the "kandi" jewellery that fluoresces under ultraviolet light. They contain words or phrases that are unique to the raver and that they can choose to trade with each other using "PLUR" (Peace, Love, Unity, Respect). This style of attire was again taken up by the fashion industry and marketed as "rave fashion" or "festival fashion", now includling all kinds of accessories to create unique looks depending on event.
|
|
Internal controls are also necessary to normalise for differences in transfection efficiencies and gene expression in different cells. This is accomplished by co-transfecting cells with plasmids encoding the fusion proteins of interest as well as a whole (non-fragmented) protein that fluoresces at a different wavelength from the fluorescent reporter protein. During visualisation, one determines the fluorescence intensities of the BiFC complex and the internal control which, after subtracting background signal, becomes a ratio. This ratio represents the BiFC efficiency and can be compared with other ratios to determine the relative efficiencies of the formation of different complexes.
|
|
It fluoresces light blue under both long- and short-wave UV light, and is phosphorescent under short-wave UV light. Witherite forms in low- temperature hydrothermal environments. It is commonly associated with fluorite, celestine, galena, barite, calcite, and aragonite. Witherite occurrences include: Cave-in-Rock, Illinois, US; Pigeon Roost Mine, Glenwood, Arkansas, US; Settlingstones Mine Northumberland; Alston Moor, Cumbria; Anglezarke, Lancashire and Burnhope,Ashburn, J.H., Mining Witherite in North- West Durham, Colliery Guardian, August 1963 (at Durham Mining Museum web-site) County Durham, England; Thunder Bay area, Ontario, Canada, Germany, and Poland (Tarnowskie Góry and Tajno at Suwałki Region).
|
|
The red photophore of Malacosteus consists of a pigmented sac with a reflective inner lining and an internal mass of gland cells. Inside the gland cells, blue-green light is produced via the same chemical reaction found in other stomiids, which is then absorbed by a protein that fluoresces in a broad red band. This light is then reflected out through the photophore apterture, where it passes through a brown filter, yielding a far-red light with a maximum absorbance at 708 nm (almost infrared). In live fish, the suborbital and postorbital photophores both flash vigorously, the suborbital at a slower rate.
|
|
In the case of SYBR green (which fluoresces 1000-fold more intensely while intercalated in the minor groove of two strands of DNA), the dissociation of the DNA during heating is measurable by the large reduction in fluorescence that results. Alternatively, juxtapositioned probes (one featuring a fluorophore and the other, a suitable quencher) can be used to determine the complementarity of the probe to the target sequence. The graph of the negative first derivative of the melting- curve may make it easier to pin-point the temperature of dissociation (defined as 50% dissociation), by virtue of the peaks thus formed. SYBR Green enabled product differentiation in the LightCycler in 1997.
|
|
The latent loads (humidity) from occupants, infiltration and processes generally need to be managed by an independent system. Radiant cooling may also be integrated with other energy-efficient strategies such as night time flushing, indirect evaporative cooling, or ground source heat pumps as it requires a small difference in temperature between desired indoor air temperature and the cooled surface. Fluorescent radiant cooling uses a coating that fluoresces in the infrared atmospheric window, a frequency range where the atmosphere is unusually transparent, so that the energy goes straight out to space. This can cool the heat-fluorescent object to below ambient air temperature, even in full sun.
|
|
Fluorescence intensity detection has developed very broadly in the microplate format over the last two decades. The range of applications is much broader than when using absorbance detection, but the instrumentation is usually more expensive. In this type of instrumentation, a first optical system (excitation system) illuminates the sample using a specific wavelength (selected by an optical filter, or a monochromator). As a result of the illumination, the sample emits light (it fluoresces) and a second optical system (emission system) collects the emitted light, separates it from the excitation light (using a filter or monochromator system), and measures the signal using a light detector such as a photomultiplier tube (PMT).
|
|
In the first stage, the LED produces one color of light, similar to any other LED. In the second stage, some of the blue or violet-blue is absorbed by a phosphor, which fluoresces yellow, imitating the broad spectrum of colors which the eye perceives as "white". This is essentially the same process used in fluorescent lamps, except for the use of an LED to create blue light rather than excited gas plasma to create ultraviolet. White LEDs can be used as white holiday lights or to create any other color through the use of colored refractors and lenses similar to those used with incandescent bulbs.
|
|
T-1824 or Evans blue, often incorrectly rendered as Evan's blue, is an azo dye that has a very high affinity for serum albumin. Because of this, it can be useful in physiology in estimating the proportion of body water contained in blood plasma. It fluoresces with excitation peaks at 470 and 540 nm and an emission peak at 680 nm. Evans blue dye has been used as a viability assay on the basis of its penetration into non-viable cells, although the method is subject to error because it assumes that damaged or otherwise altered cells are not capable of repair and therefore are not viable.
|
|
Several fluorescent protein exist in nature, but the most important one as a research tool is Green Fluorescent Protein (GFP) from the jellyfish Aequorea victoria, which spontaneously fluoresces upon folding via specific serine-tyrosine- glycine residues. The benefit that GFP and other fluorescent proteins have over organic dyes or quantum dots is that they can be expressed exogenously in cells alone or as a fusion protein, a protein that is created by ligating the fluorescent gene (e.g., GFP) to another gene and whose expression is driven by a housekeeping gene promoter or another specific promoter. This approach allows fluorescent proteins to be used as reporters for any number of biological events, such as sub-cellular localization and expression patterns.
|
|
In fluorite, the visible light emitted is most commonly blue, but red, purple, yellow, green, and white also occur. The fluorescence of fluorite may be due to mineral impurities, such as yttrium and ytterbium, or organic matter, such as volatile hydrocarbons in the crystal lattice. In particular, the blue fluorescence seen in fluorites from certain parts of Great Britain responsible for the naming of the phenomenon of fluorescence itself, has been attributed to the presence of inclusions of divalent europium in the crystal. One fluorescent variety of fluorite is chlorophane, which is reddish or purple in color and fluoresces brightly in emerald green when heated (thermoluminescence), or when illuminated with ultraviolet light.
|
|
Fluorescence microscopy relies upon fluorescent compounds, or fluorophores, in order to image biological systems. Since fluorescence and phosphorescence are competitive methods of relaxation, a fluorophore that undergoes intersystem crossing to the triplet excited state no longer fluoresces and instead remains in the triplet excited state, which has a relatively long lifetime, before phosphorescing and relaxing back to the singlet ground state so that it may continue to undergo repeated excitation and fluorescence. This process in which fluorophores temporarily do not fluoresce is called blinking. While in the triplet excited state, the fluorophore may undergo photobleaching, a process in which the fluorophore reacts with another species in the system, which can lead to the loss of the fluorescent characteristic of the fluorophore.
|
|
In one of his best known works, Alba, presented in 2000 in Avignon, France, Kac claimed to have commissioned a French laboratory to create a green- fluorescent rabbit; a rabbit implanted with a Green Fluorescent Protein (GFP) gene from a type of jellyfish. Under a specific blue light, the rabbit fluoresces green. The work proved to be hugely controversial, which was later mitigated by the revelation that the GFP process was not new but was, rather, already in use on rabbits at the lab in question. Kac's original aim was for Alba to live with his family, but prior to the scheduled release of Alba to Kac, the lab retracted their agreement and decided that Alba should remain in the lab.
|
|
To overcome these challenges, chemists have opted to proceed by identifying pairs of bioorthogonal reaction partners, thus allowing the use of small exogenous molecules as biomolecular probes. A fluorophore can be attached to one of these probes to give a fluorescence signal upon binding of the reporter molecule to the target—just as GFP fluoresces when it is expressed with the target. Now limitations emerge from the chemistry of the probe to its target. In order for this technique to be useful in biological systems, click chemistry must run at or near biological conditions, produce little and (ideally) non-toxic byproducts, have (preferably) single and stable products at the same conditions, and proceed quickly to high yield in one pot.
|
|
In some cases, the concentration of the activator must be restricted to below a certain level, to prevent quenching of the fluorescent emission. Furthermore, the mineral must be free of impurities such as iron or copper, to prevent quenching of possible fluorescence. Divalent manganese, in concentrations of up to several percent, is responsible for the red or orange fluorescence of calcite, the green fluorescence of willemite, the yellow fluorescence of esperite, and the orange fluorescence of wollastonite and clinohedrite. Hexavalent uranium, in the form of the uranyl cation, fluoresces at all concentrations in a yellow green, and is the cause of fluorescence of minerals such as autunite or andersonite, and, at low concentration, is the cause of the fluorescence of such materials as some samples of hyalite opal.
|
|
The novel opens as Dr. Kay Scarpetta, Chief Medical Examiner for the Commonwealth of Virginia, receives an early-morning call from Sergeant Pete Marino, a homicide detective at the Richmond Police Department with whom Scarpetta has a tense working relationship. She meets him at the scene of a woman's gruesome strangling, the latest in a string of unsolved murders in Richmond. The killer leaves behind a few clues; among them are a mysterious substance which fluoresces under laser light, which was later on proved to be from a liquid soap which the killer used to wash his hands, traces of semen, and in the vicinity of the last murder, an unusual smell. Scarpetta and Marino work with FBI profiler Benton Wesley to attempt to piece together a profile of the killer.
|
|