Antiserum reagent 84997

polyclonal antibodyantigenfor bacterial cultures

O antigens are thermostable lipopolysaccharides (LPS) found in the outer membrane of E. coli. 188 different O antigens are known, designated O1 to O188. 0188 is internationally recognized as a new serotype, though it has not been published. Some O antisera cross-react with antigens from other bacteria, e.g. Shigella and Salmonella, as the O antigens from these species are partly or entirely identical. Before serotyping, it is therefore important that the identification of E. coli is confirmed, e.g. with biochemical reactions. The O groups do not correlate with the presence of specific virulence factors. This must be investigated separately. Product description O antisera are polyclonal antibodies produced by immunising rabbits with boiled cells. Since the boiling removes all H, K and F antigens, cross-reactions with these are rarely seen. In order to minimise cross-reaction problems, the majority of SSI Diagnostica E. coli O antisera are supplied as monospecific antisera, i.e. free of known O cross-reactions. SSI Diagnostica offers O pool antisera and single O antisera (see the descriptions under ‘product range’) supplied in bottles of 1 mL ready-to-use antisera (the most frequent O serotypes are also available in 3 mL vials). 1 mL ready-to-use antisera is sufficient for at least 7 tests in Widal tubes or 12 tests in microtitre plates. In addition, SSI Diagnostica also offers high-titre single O antisera (if the titer allows) supplied in 1 mL bottles for dilution by the customer (minimum dilution 1:4), thus providing a quantity sufficient for at least 25 test in Widal tubes or 50 tests in microtitre plates.