When we inject four replicates of a test sample, the signal in the firs=
t
run is 20-30% lower than in the three that follow, which are in pretty go=
od
agreement. This happens whether the replicates are obtained by sampling =
the
same vial four times, or by sampling four separate vials once each.
Moreover, a blank run follows every test run, and shows no significant
peaks, so it's hard to see how some sort of cross contamination is
occurring. =20
All insights gratefully received!
John Holt
Pasteur M=E9rieux Connaught