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F7250

Sigma-Aldrich

Fluorescein isothiocyanate isomer I

≥90% purity (HPLC), powder

Synonym(s):

FITC, Fluorescein 5-isothiocyanate

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About This Item

Empirical Formula (Hill Notation):
C21H11NO5S
CAS Number:
Molecular Weight:
389.38
Beilstein:
1407295
EC Number:
MDL number:
UNSPSC Code:
12171500
PubChem Substance ID:
NACRES:
NA.47

product name

Fluorescein isothiocyanate isomer I, suitable for protein labeling, ≥90% (HPLC), powder

Quality Level

Assay

≥90% (HPLC)

form

powder

color

orange to dark orange

mp

>360 °C (lit.)

solubility

acetone: 1 mg/mL

fluorescence

λex 492 nm; λem 518 nm (green)

suitability

suitable for protein labeling

application(s)

diagnostic assay manufacturing
hematology
histology

storage temp.

2-8°C

SMILES string

Oc1ccc2c(Oc3cc(O)ccc3C24OC(=O)c5cc(ccc45)N=C=S)c1

InChI

1S/C21H11NO5S/c23-12-2-5-16-18(8-12)26-19-9-13(24)3-6-17(19)21(16)15-4-1-11(22-10-28)7-14(15)20(25)27-21/h1-9,23-24H

InChI key

MHMNJMPURVTYEJ-UHFFFAOYSA-N

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General description

Fluorescein isothiocyanate (FITC) is yellow-orange in color with an absorption maximum at 495nm. Upon excitation, it emits a yellow-green color with an emission maximum at 525nm.
It is widely used to attach a fluorescent label to proteins via the amine group. The isothiocyanate group reacts with amino terminal and primary amines in proteins. It has been used for the labeling of proteins including antibodies and lectins.
Fluorescein isothiocyanate isomer I has been proposed as a contact sensitizer.

Application

Reagent for the FITC labeling of proteins; microsequencing of proteins and peptides (HPLC)
Biological applications include use as a fluorescent labeling reagent for proteins, a fluorescent reagent for protein tracing, and a reagent in the fluorescent antibody technique for the rapid identification of pathogens. It may be employed as the derivatization reagent for amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine and P-phenylethylamine in human urine during their capillary electrophoretic (CE) determination. It may be used for the preparation of fluorescent antibodies. It was employed for in vitro sensitization studies.
Reagent for the FITC labeling of proteins; Microsequencing of proteins and peptides (HPLC)

Pictograms

Health hazard

Signal Word

Danger

Hazard Statements

Hazard Classifications

Resp. Sens. 1 - Skin Sens. 1

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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  1. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  2. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  3. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  4. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  5. After the FITC (e.g., Product No. F7250) is conjugated to the protein, what is the solution stability of the conjugated protein?

    The stability of the conjugated protein will be essentially the stability of the unconjugated protein.  Some conjugated proteins might be stable when stored at -20°C and other conjugated proteins will have better solution stability at 2-8°C  If the protein concentration is too low, this also has a negative effect upon the stability of the conjugated protein.

  6. Is Product No. F7250, Fluorescein isothiocyanate isomer I, pharmaceutical grade?

    No. The product is considered suitable for research use only.

  7. How stable is FITC Isomer 1 (e.g., Product No. F7250) once conjugated to an antibody?

    FITC can photo bleach fairly rapidly. The prepared solution should be stored in a dark container and protected from light. When viewing the antibody staining under a microscope, it is advisable to use subdued fluorescent light when possible. If the fluorescent light stays at one position for too long, photo bleaching is noticeable.

  8. Is the intensity of FITC (e.g., Product No. F7250) pH dependent?

    Yes; many articles have reported the pH dependence of the fluorescence of fluorescein derivatives. See the following references: Archives Biochem. Biophys., 133, 263 (1969); J. Immunol., 95, 1165 (1966); Archives Biochem. Biophys., 73, 1 (1958); Standard test for labeling efficiency of FITC with BSA: NCCLS Approved Standard: ASM-1, 2nd ed., June, 1975; Characterization of FITC-dyes by IR and TLC: Analytical Biochem., 29, 526 (1969); Fluorescent labeling of proteins: Proc. Nat. Acad. Sci.,  72, 459 (1975); Amer. J. Pathol., 34, 1081 (1958); Fluorescent labeling of a lectin: Meth. Enzymol., 81, 65 (1982).

  9. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

A Ramseier et al.
Electrophoresis, 19(16-17), 2967-2975 (1998-12-31)
Amines can easily be derivatized with fluorescein isothiocyanate isomer I (FITC) and analyzed by capillary electrophoresis (CE) using alkaline buffers with or without dodecyl sulfate micelles. This paper reports the CE analysis of FITC-derivatized amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine and beta-phenylethylamine in
Chromatographically pure fluorescein and tetramethylrhodamine isothiocyanates.
L C FELTON et al.
Analytical biochemistry, 2, 178-180 (1961-04-01)
Test of a two-pathway model for small-solute exchange across the capillary wall.
Fu BM
The American Journal of Physiology, 274, H2062-H2062 (1998)
S E Macatonia et al.
Immunology, 59(4), 509-514 (1986-12-01)
Lymph node cells taken 24 hr after skin-painting mice with the contact sensitizer fluorescein isothiocyanate (FITC) induce delayed-type hypersensitivity in recipient mice. Skin-painting increased the number of dendritic cells (DC) in the draining lymph nodes without significantly changing the number
Handbook of Affinity Chromatography (2005)

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