Description
Product Usage Information
Prior to use, thaw the recombinant protein and briefly spin down to collect all liquid at the bottom of the tube. Dilute according to the following instructions depending on the ELISA kit type. An example sensitivity curve is shown in Figure 2. PathScan ® ELISA Kits: Dilute with ELISA Sample Diluent to achieve a 1X protein concentration. PathScan ® RP ELISA Kits: Dilute with 1X Cell Lysis Buffer #9803 to a 2X protein concentration to achieve a final 1X protein concentration upon addition of the detection antibody. FastScan™ ELISA Kits: Dilute with 1X FastScan™ ELISA Cell Extraction Buffer to a 2X protein concentration to achieve a final 1X protein concentration upon addition of the antibody cocktail.
Formulation
Expression Host: E. coli Supplied in 10 mM Tris-HCl (pH 7.4), 0.1 mM EDTA, 1 mM DTT, 300 mM NaCl, and 50% (v/v) glycerol.
Storage
Store at -20°C.
Background
The CRISPR associated protein 9 (Cas9) is an RNA-guided DNA nuclease and part of the CRISPR antiviral immunity system that provides adaptive immunity against extra chromosomal genetic material (1). The CRISPR antiviral mechanism of action involves three steps: (i), acquisition of foreign DNA by host bacterium; (ii), synthesis and maturation of CRISPR RNA (crRNA), followed by the formation of RNA-Cas nuclease protein complexes; and (iii), target interference through recognition of foreign DNA by the complex and its cleavage by Cas nuclease activity (2). The type II CRISPR/Cas antiviral immunity system provides a powerful tool for precise genome editing and has potential for specific gene regulation and therapeutic applications (3). The Cas9 protein and a guide RNA consisting of a fusion between a crRNA and a trans-activating crRNA (tracrRNA) must be introduced or expressed in a cell. A 20-nucleotide sequence at the 5' end of the guide RNA directs Cas9 to a specific DNA target site. As a result, Cas9 can be "programmed" to cut various DNA sites both and in cells and organisms. CRISPR/Cas9 genome editing tools have been used in many organisms, including mouse and human cells (4,5). Research studies demonstrate that CRISPR can be used to generate mutant alleles or reporter genes in rodents and primate embryonic stem cells (6-8). Cas9 ( ) is a Cas9 ortholog that is smaller, but as efficient, as the more commonly used Cas9 ortholog, Cas9 ( ) (9).
