Fluorescein

Source: Wikipedia, the free encyclopedia.
This article is about the dye and fluorescent tracer. For the use of fluorescein as a medication, see Fluorescein (medical use).
Fluorescein
Skeletal formula
Ball-and-stick model
Sample of dark red powder
Names
Pronunciation /flʊəˈrɛsi.ɪn, flʊəˈrɛsiːn/
IUPAC name
3′,6′-dihydroxyspiro[isobenzofuran-1(3H),9′-[9H]xanthen]-3-one
Other names
Fluorescein, resorcinolphthalein, C.I. 45350, solvent yellow 94, D & C yellow no. 7, angiofluor, Japan yellow 201, soap yellow
Identifiers
3D model (
JSmol
)
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard
 100.017.302 Edit this at Wikidata
EC Number
  • 219-031-8
KEGG
MeSH Fluorescein
UNII
  • InChI=1S/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 checkY
    Key: GNBHRKFJIUUOQI-UHFFFAOYSA-N checkY
  • 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
    Key: GNBHRKFJIUUOQI-UHFFFAOYAZ
  • c1ccc2c(c1)C(=O)OC23c4ccc(cc4Oc5c3ccc(c5)O)O
Properties
C20H12O5
Molar mass 332.311 g·mol−1
Melting point 314 to 316 °C (597 to 601 °F; 587 to 589 K)
Slightly
Pharmacology
S01JA01 (WHO)
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H319
P305, P338, P351
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Fluorescein is an

fluorescent tracer for many applications.[1]

The color of its aqueous solutions is green by reflection and orange by transmission (its spectral properties are dependent on

colorant to the alcohol
filling the tube in order to increase the visibility of the air bubble contained within. More concentrated solutions of fluorescein can even appear red (because under these conditions nearly all incident emission is re-absorbed by the solution).

It is on the World Health Organization's List of Essential Medicines.[3]

Uses

Main article: Fluorescein (medical use)

Fluorescein sodium, the sodium salt of fluorescein, is used extensively as a diagnostic tool in the field of

rigid gas permeable contact lens fitting to evaluate the tear layer under the lens. It is available as sterile single-use sachets containing lint-free paper applicators soaked in fluorescein sodium solution.[4]

The thyroxine ester of fluorescein is used to quantify the

thyroxine concentration in blood.[1]

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.

Fluorescein is a precursor to the red dye eosin Y by bromination.[1]

Safety

Oral and intravenous use of fluorescein can cause

anaphylactic shock.[8][9]

Intravenous use has the most reported adverse reactions, including sudden death, but this may reflect greater use rather than greater risk. Both oral and topical uses have been reported to cause anaphylaxis,

prophylactic) use of antihistamines[16]
and prompt emergency management of any ensuing anaphylaxis.[17] A simple prick test may help to identify persons at greatest risk of adverse reaction.[15]

Chemistry

Fluorescein under UV illumination
Fluorescence excitation and emission spectra of fluorescein

The fluorescence of this molecule is very intense; peak excitation occurs at 495 nm and peak emission at 520 nm. Values for the deprotonated form in basic solution.

Fluorescein has a

ring-opened products.[18]

Fluorescein has an isosbestic point (equal absorption for all pH values) at 460 nm.

Derivatives

Fluorescein isothiocyanate and 6-FAM phosphoramidite

Many derivatives of fluorescein are known. Examples are:

In oligonucleotide synthesis, several phosphoramidite reagents containing protected fluorescein, e.g. 6-FAM phosphoramidite 2,[19] are used for the preparation of fluorescein-labeled oligonucleotides.

The extent to which fluorescein dilaurate is broken down to yield lauric acid can be detected as a measure of pancreatic esterase activity.

Synthesis

Approximately 250 tons/y were produced in the year 2000. The method involves the fusion of

Friedel-Crafts reaction.[21][22]

Research

Fluorescein is a

absorption maximum at 494 nm and emission maximum of 512 nm (in water). The major derivatives are fluorescein isothiocyanate (FITC) and, in oligonucleotide synthesis, 6-FAM phosphoramidite
.

Biosciences

See also: Fluoro-jade stain

In cellular biology, the

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
.

Fluorescein can also be conjugated to

antibodies using immunohistochemistry. The latter is a common alternative to digoxigenin, and the two are used together for labelling two genes in one sample.[23]

Fluorescein drops being instilled for an eye examination

Intravenous or oral fluorescein is used in

tumors. It is also being used increasingly during surgery for brain and spine tumors.[24]

Diluted fluorescein dye has been used to localise multiple muscular ventricular septal defects during open heart surgery and confirm the presence of any residual defects.[25]

splashdown
, June 1965.

Earth sciences

Fluorescein is used as a rather conservative

methylated spirit
dye.

As fluorescein solution changes its color depending on concentration,[26] it has been used as a tracer in evaporation experiments.

One of its more recognizable uses was in the

St. Patrick's Day in 1962. In 1966, environmentalists forced a change to a vegetable-based dye to protect local wildlife.[27]

Fluorescein dye solutions, typically 15% active, are commonly used as an aid to leak detection during

pipelines and other subsea infrastructure. Leaks can be detected by divers or ROVs
carrying an ultraviolet light.

Plant science

Fluorescein has often been used to track water movement in groundwater to study water flow and observe areas of contamination or obstruction in these systems. The fluorescence that is created by the dye makes problem areas more visible and easily identified. A similar concept can be applied to plants because the dye can make problems in plant vasculature more visible. In plant science, fluorescein, and other fluorescent dyes, have been used to monitor and study plant vasculature, particularly the xylem, which is the main water transportation pathway in plants. This is because fluorescein is xylem-mobile and unable to cross plasma membranes, making it particularly useful in tracking water movement through the xylem.[28] Fluorescein can be introduced to a plant's veins through the roots or a cut stem. The dye is able to be taken up into the plant the same way as water and moves from the roots to the top of the plant due to a transpirational pull.[29] The fluorescein that has been taken up into the plant can be visualized under a fluorescent microscope.

See also

References

  1. ^
    ISBN 978-3527306732
    .
  2. ^
    ISSN 1386-1425
    .
  3. hdl:10665/325771
    . WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO.
  4. PMID 20325960
    .
  5. PMID 9673591. Archived
    (PDF) from the original on 2015-07-24.
  6. ^ The diagnosis and management of anaphylaxis: an updated practice parameter. Archived 2007-08-05 at the Wayback Machine National Guideline Clearinghouse.
  7. ^
    PMID 8952662
    .
  8. PMID 10356782
    .
  9. S2CID 71681503
    .
  10. PMID 3195657
    .
  11. PMID 1882930
    .
  12. S2CID 32809716
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  13. PMID 7930354
    .
  14. ^
    PMID 1891225
    .
  15. ^
    PMID 8644545
    .
  16. PMID 7257056
    .
  17. PMID 17698436
    .
  18. S2CID 253266074
    .
  19. ^ Brush, C. K. "Fluorescein Labelled Phosphoramidites". U.S. patent 5,583,236. Priority date July 19, 1991.
  20. ^ Baeyer, Adolf (1871) "Uber ein neue Klasse von Farbstoffen" Archived 2016-06-29 at the Wayback Machine (On a new class of dyes), Berichte der Deutschen chemischen Gesellschaft zu Berlin, 4 : 555-558; see p. 558.
  21. doi:10.1021/jo9706178
    .
  22. doi:10.1055/s-2004-829194
    .
  23. S2CID 46010136. Archived from the original (PDF) on 2007-09-28. Retrieved 2007-07-16.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  24. PMID 36248155
    .
  25. PMID 24384220
    .
  26. ^ Käss, W. Tracing Technique in Geohydrology. Rotterdam: Balkema.
  27. ^ The Story Behind Dyeing the River Green. Greenchicagoriver.com. Retrieved on 2014-08-28.
  28. PMID 25588734
    .
  29. PMID 34286014
    .

External links

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