2321-07-5 Usage
Description
Fluorescein is a synthetic organic compound available as a dark orange/red powder slightly soluble in water and alcohol. It is widely used as a fluorescent tracer for many applications. Fluorescein is a fluorophore commonly used in microscopy, in a type of dye laser as the gain medium, in forensics and serology to detect latent blood stains, and in dye tracing. Fluorescein has an absorption maximum at 494 nm and emission maximum of 521 nm (in water). The major derivatives are fluorescein isothiocyanate (FITC) and, in oligonucleotide synthesis, 6-FAM phosphoramidite. Fluorescein also has an isosbestic point (equal absorption for all pH values) at 460 nm. Fluorescein is also known as a color additive (D&C Yellow no. 7). The disodium salt form of fluorescein is known as uranine or D&C Yellow no. 8. The color of its aqueous solution varies from green to orange as a function of the way it is observed: by reflection or by transmission, as it can be noticed in bubble levels in which fluorescein is added as a colorant to the alcohol filling the tube to increase the visibility of the air bubble and the precision of the instrument. More concentrated solutions of fluorescein can even appear red.
Chemical Properties
Orange-red, crystalline powder. Very
dilute alkaline solutions exhibit intense greenishyellow fluorescence by reflected light, while the
solution is reddish-orange by transmitted light.soluble in dilute alkalies, boiling alcohol, ether, dilute acids, and
Physical properties
The fluorescence of this molecule is very intense; peak excitation occurs at 494 nm and peak emission at 521 nm. Fluorescein has a pKa of 6.4, and its ionization equilibrium leads to pH-dependent absorption and emission over the range of 5 to 9. Also, the fluorescence lifetimes of the protonated and deprotonated forms of fluorescein are approximately 3 and 4 ns, which allows for pH determination from non intensity based measurements. The lifetimes can be recovered using time-correlated single photon counting or phase-modulation fluorimetry.
Uses
Different sources of media describe the Uses of 2321-07-5 differently. You can refer to the following data:
1. Fluorescein is used as a fluorescent tracer for many applications including in a type of dye laser as the gain medium, in forensics and serology to detect latent blood stains and in dye tracing. It is used to localise multiple muscular ventricular septal defects during open heart surgery and confirm the presence of any residual defects. It is applied to teeth to reveal plaque.
2. A fluorescent tracer used for many applications. It is used in ophthalmology as a tool in the diagnosis of corneal abrasions, corneal ulcers and herpetic corneal infections. It can attach to certain biologically active molecules, thus allowing biologists to target the fluorophore to specific proteins or structures within cells
3. corneal trama indicator
Definition
Different sources of media describe the Definition of 2321-07-5 differently. You can refer to the following data:
1. ChEBI: A xanthene dye that is highly fluorescent, detectable even when present in minute quantities. Used forensically to detect traces of blood, in analytical chemistry as an indicator in silver nitrate titrations and in microscopy.
2. A fluorescent
dye used as an absorption indicator.
Application
Biochemical research In cellular biology, the isothiocyanate derivative of fluorescein is often used to label and track cells in fluorescence microscopy applications (for example, flow cytometry). Additional biologically active molecules (such as antibodies) may also be attached to fluorescein, allowing biologists to target the fluorophore to specific proteins or structures within cells. This application is common in yeast display. Health care applications "Fluorescein sodium", the sodium salt of fluorescein, is used extensively as a diagnostic tool in the field of ophthalmology and optometry, where topical fluorescein is used in the diagnosis of corneal abrasions, corneal ulcers and herpetic corneal infections. It is also used in rigid gas permeable contact lens fitting to evaluate the tear layer under the lens. Uses in river systems In 1966, environmentalists forced a change to a vegetable-based dye to protect local wildlife. Other uses of fluorescein include using it as a water-soluble dye added to rainwater in environmental testing simulations to aid in locating and analyzing any water leaks, and in Australia and New Zealand as a methylated spirit dye. Oil field application Fluorescein dye solutions, typically 15 % active, are commonly used as an aid to leak detection during hydrostatic testing of sub sea oil and gas pipelines and other subsea infrastructure. Leaks can be detected by divers carrying ultraviolet lights.
General Description
Yellow amorphous solid or orange-red crystals. Latter have greenish-yellow fluorescence by reflected light. Insoluble in water. Soluble in dilute aqueous bases. Very dilute alkaline solutions exhibit intense, greenish-yellow fluorescence by reflected light. Low toxicity. May be sensitive to prolonged exposure to light.
Air & Water Reactions
Insoluble in water.
Reactivity Profile
Fluorescein is incompatible with strong oxidizers. Also incompatible with acids, acid salts and salts of heavy metals. .
Fire Hazard
Flash point data for Fluorescein is not available, but Fluorescein is probably combustible.
Safety Profile
Poison by intravenous
route. Moderately toxic by intraperitoneal
route. Mutation data reported. When heated
to decomposition it emits acrid smoke and
irritating fumes. See also FLUORESCEIN SODIUM.
Safety
Topical, oral, and intravenous use of fluorescein can cause adverse reactions, including nausea, vomiting, hives, acute hypotension, anaphylaxis and related anaphylactoid reaction, causing cardiac arrest and sudden death due to anaphylactic shock. The most common adverse reaction is nausea, due to a difference in the pH from the body and the pH of the sodium fluorescein dye; a number of other factors , however, are considered contributors as well. The nausea usually is transient and subsides quickly. Hives can range from a minor annoyance to severe, and a single dose of antihistamine may give complete relief. Anaphylactic shock and subsequent cardiac arrest and sudden death are very rare, but because they occur within minutes, a health care provider who uses fluorescein should be prepared to perform emergency resuscitation.
Synthesis
Fluorescein was first synthesized by Adolf von Baeyer in 1871. It can be prepared from phthalic anhydride and resorcinol in the presence of zinc chloride via the Friedel - Crafts reaction. A second method to prepare fluorescein uses methanesulfonic acid as a Br?nsted acid catalyst. This route has a high yield under milder conditions.
Derivatives
There are many fluorescein derivatives. For example, fluorescein isothiocyanate 1, often abbreviated as FITC, is the original fluorescein molecule functionalized with an isothiocyanate group ( - N = C = S ) , replacing a hydrogen atom on the bottom ring of the structure. This derivative is reactive towards primary amine groups of biologically relevant compounds including intracellular proteins to form a thiourea linkage. A succinimidyl ester functional group attached to the fluorescein core, creating NHS-fluorescein, forms another common amine-reactive derivative, yielding more stable amide adducts. Penta fluoro phenyl esters (PFP) and tetra fluoro phenyl esters (TFP) are other useful reagents. In oligonucleotide synthesis, several phosphoramidite reagents containing protected fluorescein, e.g. 6-FAM phosphoramidite 2, are widely used for the preparation of fluorescein-labeled oligonucleotides. Other green dyes include Oregon Green, Tokyo Green, SNAFL, and carboxy naphtho fluorescein. These dyes, along with newer fluoro phores such as Alexa 488, Fluo Probes 488 and DyLight 488, have been tailored for various chemical and biological applications where higher photo stability, different spectral characteristics, or different attachment groups are needed.
Check Digit Verification of cas no
The CAS Registry Mumber 2321-07-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 2,3,2 and 1 respectively; the second part has 2 digits, 0 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 2321-07:
(6*2)+(5*3)+(4*2)+(3*1)+(2*0)+(1*7)=45
45 % 10 = 5
So 2321-07-5 is a valid CAS Registry Number.
InChI:InChI=1/C20H12O5/c21-11-5-7-15-17(9-11)24-18-10-12(22)6-8-16(18)20(15)14-4-2-1-3-13(14)19(23)25-20/h1-10,21-22H
2321-07-5Relevant articles and documents
DESIGN, SYNTHESIS, AND PHOTOPHYSICAL PROPERTIES OF A NOVEL NIR II DYE FOR BIOLOGICAL IMAGING AND OPTOELECTRONIC DEVICES
-
, (2022/03/04)
In one aspect, the disclosure relates to fluorescent dyes that absorb and emit in the near infrared II (NIR II) range of the electromagnetic spectrum, methods of making same, compositions comprising same and methods of using the compositions to perform imaging on biological samples, and optoelectronic devices using the dyes. The dyes are small organic molecules that are inexpensive and facile to produce, can be water-soluble, have tunable properties, and are biocompatible and/or possess low toxicity.
Chemistry of the carboxylic acid of dihydrofluorescein in oxidation and its application to fluorogenic ROS sensing
Le, Hoa Thi,Nguyen, Dinh Phi Long,Shin, Hyo Seob,Jung, Woong,Kang, Chulhun,Kim, Tae Woo
, p. 461 - 468 (2021/07/19)
The conjugation site of dihydrofluorescein (H2F) is important for the rational design of H2F-based reactive oxygen species (ROS) sensors. Despite the prevalence of H2F analogs detecting cellular ROS, the role of the carboxylic acid of H2F in oxidation is still unclear. To get insight into the conjugation site of H2F, we synthesized H2F diacetate (2) and its amide derivative (3). The absorption and emission spectra of deacetylated 2 and 3 in the presence of H2O2/hematin showed that the carboxylic acid of H2F plays a crucial role in the oxidation of H2F. NMR and HPLC analysis of the oxidation product of deacetylated 3 showed a quantitative and fast generation of non-fluorescent spirolactam (F-Lactam). As regards these observations, we untouched the carboxylic acid at the 3rd position and designed an H2F-based ROS sensor (7) that conjugated the lipophilic chain at the 5th position instead. A series of confocal microscopic experiments of 7 demonstrated that 7 prefers the ER location and that ROS are elevated in the cells by ER stress inducers.
H2S donors with optical responses
Pluth, Michael D.,Zhao, Yu,Cerda, Matthew M.
, p. 149 - 164 (2020/06/27)
Reactive sulfur species, including hydrogen sulfide (H2S), are important biological mediators and play key roles in different pathophysiological conditions. Small molecules that release H2S on demand, often referred to as “H2S donors,” constitute a key investigative tool for H2S-related research. A significant challenge, however, is correlating the rate of H2S release from such donors in complex systems with biological outcomes, because release rates are commonly perturbed by different biological environments. In this chapter, we outline an approach to use H2S donors that provide a fluorescent response upon H2S release to address this problem. These compounds leverage the intermediate release of carbonyl sulfide (COS), which is quickly converted to H2S by the endogenous enzyme carbonic anhydrase (CA), to provide activatable donors with an optical response. The described donors are activated by biological thiols and provide a fluorescence response that correlates directly with H2S delivery, which allows for delivered H2S levels to be measured in real time by fluorescence techniques.
