Re: Bobby Waugh.

Originally from: Bill
                        
Hello again Jane,

Just to clarify things the copy letter was sent to me by a farmer, not DEFRA.

I have had a look at www.farmtalking.org/science_kiching_test.html and of course Dr. Kiching would claim 100% accuracy wouldn't he?

The reality however is somewhat different.

ELISA (enzyme-linked immunosorbent assay) is 1950's technology used because it can be automated and therefore deal with large numbers of samples. Antibody in the sample is fixed by binding with a "known" antigen. The remainder of the sample is then washed away and the residue tagged with fluorescent enzyme. The test relies on visual interpretation and detectable quantity of antibody having been accumulated in the bloodstream (6 to 10 days minimum, up to 12 weeks maximum). Also, of course, one has to assume the the correct "known" antigen is being used.

The Virus Neutralisation Test uses "known" antibody to neutralise virus ("does exactly what it says on the tin" ). More accurate than ELISA but not automated and therefore time consuming. Works early on in the disease but infected animals do not always have detectable amounts of virus in the bloodstream (FMD migrates to the lymphatic system).

100% accuracy, I think not!!!!!