Streptavidin — Alexa Fluor™ 488

Streptavidin is a biotin binding protein present in the fermentation broth of the bacterium Streptomyces avidinii. Each molecule of streptavidin can bind four molecules of biotin with a high affinity constant (K_d~10 ^-15). Unlike native avidin, streptavidin is not glycosylated and has a near neutral isoelectric point (pI ~ 5-6) vs a pI of 10 for native avidin.

h3>Advantages Over Native Avidin
Unlike native egg-white avidin, streptavidin is strictly non-glycosylated and possesses a near-neutral isoelectric point (pI ~ 5-6), whereas native avidin has a highly basic pI of 10. These biochemical properties significantly reduce non-specific electrostatic and carbohydrate-directed binding to cell surfaces and tissue components, resulting in a cleaner signal and lower background noise in your assays.

Alexa Fluor™ 488 Conjugation

This specific Streptavidin product is covalently conjugated to Alexa Fluor™ 488, a highly photostable, bright green-fluorescent dye. Alexa Fluor™ 488 is an exceptional alternative to FITC, offering superior brightness and reduced photobleaching over time. It features an excitation maximum of 490 nm and an emission maximum of 525 nm, making it ideal for the standard FITC/GFP channel in most instruments.

Recommended Applications

Streptavidin Alexa Fluor™ 488 is extensively validated for detecting biotinylated primary antibodies and other biotinylated probes. It is highly recommended for use in Flow Cytometry (FC), Immunofluorescence (IF) microscopy, and microplate-based assays where a robust fluorescent readout is required.

Liquid

Streptavidin-Alexa Fluor™ 488 is supplied in 0.01M phosphate buffered saline (PBS) pH 7.4, containing 1.0% BSA and 0.09% sodium azide as a preservative.

Keep the streptavidin-Alexa Fluor® 488 solution undiluted at 2°–8°C. Protect from prolonged light exposure and do not freeze.

Blue Ice