Steptavidin, a bacterial protein isolated from Streptomyces avidinii, is similar to egg-white avidin in its ability to bind biotin, and has been used as a replacement for egg-white avidin because of its more favorable chemical properties.Conjugates of streptavidin are recommended for use with Biotin-SP-conjugated antibodies and Biotin-SP-conjugated ChromPure proteins.Physical State: Freeze-dried solid Storage: Store freeze-dried powder at 2-8°C. When ready to use, rehydrate with indicated volume of d. water and centrifuge if not clear. Store at 2-8°C - DO NOT FREEZE. Prepare working dilution fresh each day.Expiration date: six months from date of rehydration. However, the expiration date may be extended if the product is stored according to the recommendation and the test results are acceptable for its intended use.Buffer: 0.01M Sodium Phosphate, 0.25M NaCl, pH 7.6 Stabilizer:15 mg/ml Bovine Serum Albumin (IgG-Free, Protease-Free) Preservative:0.05% Sodium Azide Suggested Working Concentration or Dilution Range:Flow Cytometry:- 1:50-1:200 Dilution factors are presented in the form of a range because the optimal dilution is a function of many factors, such as antigen density, permeability, etc. The actual dilution used must be determined empirically.

R-Phycoerythrin

Amax: 488Emax: 580nm

Phycoerythrin (R-PE) is among several kinds of light-harvesting phycobiliproteins found in red, blue-green, and cryptomonad algae. We offer R-PE, the form found in red macrophytic algae (seaweed). After phycobiliproteins are conjugated to secondary antibodies, there is little fluorescence quenching, which results in conjugates of high specific fluorescence compared with conventional fluorophore-antibody conjugates. R-PE can be excited by light over a wide range of the visible spectrum is highly water soluble, has a relatively low isoelectric point, and lacks potentially sticky carbohydrates.

It should be noted that the relatively high molecular weight of R-PE may preclude its use in procedures requiring good penetration into cells and tissues. It is predominantly intended for surface labeling of cells for flow cytometry.