Difluorocarboxyfluorescein NHS Ester, 5-isomer (Oregon Green™ 488 Carboxylic Acid, Succinimidyl Ester, 5-isomer equivalent) is an amine-reactive fluorinated analog of fluorescein that overcomes some of the key limitations of fluorescein, including greater photostability and a lower pKa (pKa ~ 4.7 versus 6.4 for fluorescein), making its fluorescence essentially pH insensitive in the physiological pH range.
Although the mixed isomers of Difluorocarboxyfluorescein NHS Ester, is a preferred, routinely used fluorescent dye for labeling proteins, peptides and nucleotides, purification of peptide and nucleotides labeled with 5(6) isomers might be troublesome due to significant signal broadening in HPLC purification. Peptides and nucleotides labeled with a single isomer usually give better resolution in HPLC purification that is often required in the conjugation processes.
Unit Size | 5 mg, 25 mg, 100 mg |
---|---|
Reactivity | Primary amine |
Abs/Em Maxima | 496/524 nm |
Extinction coefficient | 73,000 cm-1M-1 |
Solubility | DMSO, DMF |
Spectrally similar dyes | Alexa Fluor® 488, DyLight® 488, Fluorescein |
Molecular weight | 509.38 |
Storage Conditions | -20°C. |
Shipping Conditions | Ambient temperature |
Applicable patents and legal notices are available at legal notices.
Stay in the Loop. Join Our Online Community
Products
Ordering
About Us
Application
Resources
©Vector Laboratories, Inc. 2025 All Rights Reserved.
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions. Privacy Statement
How do I Request a Quote?
To request a quote for products: