[On the titration of vaccines against pleuropneumonia. A new approach to an old problem, preliminary studies]. / Note sur le titrage des vaccins péripneumonie. Nouvelle approche d'un vieux problème, essais préliminaires.

ABSTRACT

A new technique is proposed for the titration of live vaccines against contagious bovine pleuropneumonia (CBPP). Presently, the one most widely used, combines a set of tenfold dilutions with the seeding of five tubes with samples taken from each of these latter. This technique is not very accurate or it requires a great number of tubes to increase its accuracy. The new technique starts with the same tenfold dilutions but after a relevant dilution, samples of 100 microliters are put into the eight wells of the first column of a microtitration plate and then with "glucose" medium. After a 6 to 9 days incubation time, the growth can be recorded by an indicator change of color. This technique is much faster and seems to be more precise. Furthermore the eight parallel titrations enable the results to be expressed by means and comparison of results can be statistically meaningful.