A sensitive microsphere coagulation ELISA for Escherichia coli O157:H7 using Russell's viper venom.
A microsphere coagulation enzyme-linked immunosorbent assay (MC-ELISA) using Russell's viper venom factor X activator (RVV-XA) is described for the detection of Escherichia coli O157:H7. This microtitre plate assay comprises a standard sandwich immunoassay incorporating RVV-XA as the enzyme label. Coagulation substrate together with polystyrene microspheres are added to the wells of the microtitre plate. RVV-XA initiates the coagulation cascade causing formation of an artificial clot of polystyrene microspheres bound together with fibrin. As few as 10(2) E. coli O157 in a well (10(3) per ml) can be detected within 3 h. The assay is two orders of magnitude more sensitive than a standard ELISA and is a generic technique with the potential for widespread use in sandwich immunoassays.
Strachan
N J
NJ
Department of Plant and Soil Science, University of Aberdeen, Cruickshank Building, Aberdeen, UK. n.strachan@abdn.ac.uk
Ogden
I D
ID
D003029:Coagulants; D015169:Colony Count, Microbial; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D004927:Escherichia coli Infections / Q000382:microbiology; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D005516:Food Microbiology; D006801:Humans; D008666:Metalloendopeptidases; D008863:Microspheres; D012680:Sensitivity and Specificity
D003029:Coagulants; D008666:Metalloendopeptidases; C033858:russellysin