March 2016 News

The life sciences have recently been revolutionized by the exploitation of the bacterial CRISPR system. CRISPR is an acronym for "Clustered Regularly Interspaced Short Palindromic Repeats". The short palindromes are DNA sequences generated by the bacterial host, while the DNA inserts between them are derived from infectious agents which have previously challenged the bacteria. These inserts generate a complementary RNA which can direct a DNA cutting enzyme, Cas9, to specific base sequences in the DNA of the relevant infectious agents, cutting their DNA and hence inactivating them. Cas9, which means "CRISPR associated protein 9", was originally studied in Streptococcus pyogenes and is a very large multidomain protein of 158kDa molecular weight. This is inconvenient for many purposes as the DNA needed to express it is correspondingly large, which can present problems with some DNA vector systems. A systematic search for smaller Cas9 homologues showed that Staphylococcus aureus expressed a significantly smaller version, of 124kDa, and we have made a monoclonal antibody to the the C-terminal domain of this, namely MCA-6F7. We also continue to build out our portfolio of antibodies directed against Cnidarian fluorescent proteins, with rabbit antibodies to FP506 (RPCA-FP506) from Zooanthus and EosFP (RPCA-EOSFP) from Lobophyllia hemprichii. Both antibodies are available now. We also release two mouse monoclonals to GFP, MCA-1F1 and MCA-3B11. We add an affinity purified rabbit polyclonal antibody to secretagogin, RPCA-SCGN-ap, to our collection of antibodies to small Calcium binding proteins. These are useful for subclassifying interneurons in the brain. There is a growing interest in the detection of GFAP in blood and CSF as a potential biomarker of CNS damage and disease states. Since the human and rodent proteins have some significant differences at the primary sequence level, we have now expressed full length recombinant rat GFAP, Prot-r-GFAP-rat, which is a more useful protein standard for workers using rodent models. Finally we release an excellent affinity purified antibody to laminin, RPCA-Laminin-ap, which stains blood vessels in the brain beautifully.