ESTIMATION OF TITER OF VENEZUELAN EQUINE ENCEPHALOMYELITIS VIRUS PREPARATIONS FROM A SINGLE-DILUTION ASSAY

Autor: Jean M. Riley, William C. Patrick, William E. Campbell
Rok vydání: 1963
Předmět:
Zdroj: Journal of Bacteriology. 85:1256-1260
ISSN: 1098-5530
0021-9193
DOI: 10.1128/jb.85.6.1256-1260.1963
Popis: Riley, Jean M. (U.S. Army Biological Laboratories, Fort Detrick, Frederick, Md.), William C. Patrick, III, and William E. Campbell, Jr. Estimation of titer of Venezuelan equine encephalomyelitis virus preparations from a single-dilution assay. J. Bacteriol. 85: 1256–1260. 1963.—When suspensions of Venezuelan equine encephalomyelitis (VEE) virus were injected intracerebrally into groups of mice, a nearly linear relationship was observed between the concentration of the virus injected and the mean reciprocal time-to-death of the mice. A total of 91 VEE preparations were assayed in duplicate, and, by plotting the relationship between the reciprocal time-to-death for mice given the 10 −6 dilution of virus and the micld 50 (mouse intracerebral challenge, ld 50 response) values for the virus preparations, a reference curve was established. Using this reference curve, it was possible to estimate directly the ld 50 values of virus suspensions of unknown concentration from the mean reciprocal time-to-death of a group of mice injected with a single dilution. In this work, the number of mice used was reduced by 62.5%, the titrations were complete in 3 to 5 days compared with the usual 10 to 14 days, three to four times as many assays could be done in a day, and no assays had to be repeated since end points were not missed. The precision of the single-dilution assay compared favorably with that of the ld 50 titration.
Databáze: OpenAIRE
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