Sticky Recombinant Streptavidin

Brief introduction

Name: Sticky Recombinant Streptavidin (S-rSA)

Specification: 1 mg, 10 mg, 100 mg, 500 mg

Product form: lyophilized powder, the solution before lyophilization is 5mM PB (4M Na2HPO4, 1mM NaH2PO4, pH7.4) solution

Molecular weight: subunit monomer 23.5kDa, tetramer 94kDa

Isoelectric point: 6.04

Theoretical activity: 18.1 U/mg protein (S-rSA: Biotin=1:4 (mol: mol))

Activity: ≥ 15 U/mg protein (determined by modified Green method)

Purity: ≥ 95% (SDS-PAGE detection)

Concentration determination: 280nm absorption method, molar absorption coefficient 1.68 × 105 (mol/L) – 1 • cm-1, that is, c (g/L)=A280nm/2.00

Endotoxin: ≤ 5EU/mg

Source: Escherichia coli

Storage condition: – 20 ℃

Validity: 2 years

Streptavidin (SA) is a homotetramer protein secreted by Streptomyces avidinii during its growth. Like avidin, one mole of streptavidin can bind four moles of biotin, which has high affinity with biotin. Because SA does not contain sugar groups, it has a lower non-specific binding level than avidin in detection and application, and has been widely used in enzyme-linked immunosorbent assay, immunohistochemistry, time-resolved immunofluorescence (TRFIA), quantitative PCR, single-stranded DNA preparation, biological component purification, monoclonal antibody preparation and other biotechnology fields.

However, the adsorbability of streptavidin is poor, and it is difficult to adsorb onto NC membrane or embed it in practical applications. Sticky recombinant streptavidin (S-rSA) is mainly used to solve this problem. It not only has the core sequence related to activity, but also has better adsorbability, stability, solubility and other aspects than natural SA, especially on NC membrane.

Scope of application

In many applications, such as immunocytochemistry, ELISA and immunoblotting, streptavidin alkaline phosphatase can be used to detect biotinylated molecules, such as antibodies.

Immunocytochemistry

For most applications, 1:150 working dilution in TBS is sufficient. At this dilution, about 3000 tests (100ul per slide) can be carried out for each package. It is recommended to use TBS instead of PBS in all diluents and washings to maintain maximum enzyme activity.