FAM NHS ester, 6-isomer

    WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 558785

CAS#: 92557-81-8

Description: This product contains the pure 6-isomer of fluorescein. Fluorescein (FAM) is a bright fluorophore that has found an extremely wide application in life science research. The fluorophore is hydrophilic and its derivatives possess good solubility in aqueous buffers.

Chemical Structure

FAM NHS ester, 6-isomer
CAS# 92557-81-8

Theoretical Analysis

MedKoo Cat#: 558785
Name: FAM NHS ester, 6-isomer
CAS#: 92557-81-8
Chemical Formula: C25H15NO9
Exact Mass: 473.0747
Molecular Weight: 473.39
Elemental Analysis: C, 63.43; H, 3.19; N, 2.96; O, 30.42

Price and Availability

Size Price Availability Quantity
5.0mg USD 390.0 2 weeks
25.0mg USD 700.0 2 weeks
50.0mg USD 1145.0 2 weeks
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Synonym: Fluorescein NHS ester, 6-isomer

IUPAC/Chemical Name: (2,5-dioxopyrrolidin-1-yl) 3',6'-dihydroxy-1-oxospiro[2-benzofuran-3,9'-xanthene]-5-carboxylate


InChi Code: InChI=1S/C25H15NO9/c27-13-2-5-16-19(10-13)33-20-11-14(28)3-6-17(20)25(16)18-9-12(1-4-15(18)24(32)34-25)23(31)35-26-21(29)7-8-22(26)30/h1-6,9-11,27-28H,7-8H2

SMILES Code: OC1=CC=C2C(OC(C=C(O)C=C3)=C3C24C5=CC(C(ON6C(CCC6=O)=O)=O)=CC=C5C(O4)=O)=C1

Appearance: Solid powder

Purity: >98% (or refer to the Certificate of Analysis)

Shipping Condition: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition: Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Solubility: Soluble in DMSO

Shelf Life: >3 years if stored properly

Drug Formulation: This drug may be formulated in DMSO

Stock Solution Storage: 0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code: 2934.99.9001

Preparing Stock Solutions

The following data is based on the product molecular weight 473.39 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1. Evans, L.E.; Jones, K.; Cheeseman, M.D. Targeting secondary protein complexes in drug discovery: studying the druggability and chemical biology of the HSP70/BAG1 complex. Chemical Communications, 2017, 53(37), 5167–5170. doi: 10.1039/c7cc01376k

2. Warminski, M.; Sikorski, P.J.; Warminska, Z.; Lukaszewicz, M.; Kropiwnicka, A.; Zuberek, J.; Darzynkiewicz, E.; Kowalska, J.; Jemielity, J. Amino-functionalized 5' cap analogs as tools for site-specific sequence-independent labeling of messenger RNA. Bioconjugate Chemistry, 2017, 28(7), 1978–1992. doi: 10.1021/acs.bioconjchem.7b00291

3. Horning, D.P.; Joyce, G.F. Amplification of RNA by an RNA polymerase ribozyme. Proceedings of the National Academy of Sciences of the United States of America, 2016, 113(35), 9786–9791. doi: 10.1073/pnas.1610103113