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 a fluorophore commonly used in microscopy, as a gain medium in dye lasers, in forensics and serology to detect latent blood stains, and in dye tracing. Fluorescein has an absorption maximum at 494 nm and an emission maximum of 521 nm (in water). It is also known as a color additive (D&C Yellow no. 7), and its disodium salt form is known as uranine or D&C Yellow no. 8. The color of its aqueous solution varies from green to orange depending on the observation method.
Uses
1. Used in Dye Lasers:
Fluorescein is used as a fluorescent tracer and serves as the gain medium in a type of dye laser.
2. Used in Forensic Science and Serology:
Fluorescein is employed to detect latent blood stains in forensics and serology.
3. Used in Dye Tracing:
Fluorescein is utilized as a fluorescent tracer in dye tracing applications.
4. Used in Ophthalmology:
Fluorescein is used as a diagnostic tool in ophthalmology and optometry, where it helps in the diagnosis of corneal abrasions, corneal ulcers, and herpetic corneal infections.
5. Used in Cellular Biology:
In cellular biology, the isothiocyanate derivative of fluorescein is often used to label and track cells in fluorescence microscopy applications, such as flow cytometry. It can also be attached to biologically active molecules like antibodies, allowing biologists to target specific proteins or structures within cells.
6. Used in Health Care:
"Fluorescein sodium," the sodium salt of fluorescein, is used extensively in the field of ophthalmology and optometry for diagnostic purposes.
7. Used in Environmental Testing:
Fluorescein is used as a water-soluble dye added to rainwater in environmental testing simulations to aid in locating and analyzing water leaks.
8. Used in Oil Field Applications:
Fluorescein dye solutions are commonly used as an aid to leak detection during hydrostatic testing of subsea oil and gas pipelines and other subsea infrastructure.
9. Used as a pH Indicator:
Fluorescein's pH-dependent absorption and emission properties over the range of 5 to 9 make it useful for pH determination from non-intensity-based measurements.
10. Used in Biochemical Research:
Fluorescein is employed in biochemical research for various applications, including the development of novel drug delivery systems and the study of biological interactions.
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.
Lipase mimetic cyclodextrins
Lee, Youngjun,Devaraj, Neal K.
, p. 1090 - 1094 (2021/02/06)
Glycerophospholipids (GPLs) perform numerous essential functions in biology, including forming key structural components of cellular membranes and acting as secondary messengers in signaling pathways. Developing biomimetic molecular devices that can detect specific GPLs would enable modulation of GPL-related processes. However, the compositional diversity of GPLs, combined with their hydrophobic nature, has made it challenging to develop synthetic scaffolds that can react with specific lipid species. By taking advantage of the host-guest chemistry of cyclodextrins, we have engineered a molecular device that can selectively hydrolyze GPLs under physiologically relevant conditions. A chemically modified α-cyclodextrin bearing amine functional groups was shown to hydrolyze lyso-GPLs, generating free fatty acids. Lyso-GPLs are preferentially hydrolyzed when part of a mixture of GPL lipid species, and reaction efficiency was dependent on lyso-GPL chemical structure. These findings lay the groundwork for the development of molecular devices capable of specifically manipulating lipid-related processes in living systems.
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.
