Search PubMed⌕ Search

Biomedical subjects

F T PERKINS

Publications and source records attributed to F T PERKINS.

At least 19 recordsLinked to original sources
PubMed1963

FIFTH INTERNATIONAL STANDARD FOR GAS-GANGRENE ANTITOXIN (PERFRINGENS) (CLOSTRIDIUM WELCHII TYPE A ANTITOXIN).

The Fifth International Standard Gas-Gangrene Antitoxin (Perfringens) (Clostridium welchii Type A Antitoxin) was prepared from serum from immunized horses. It was freeze-dried in ampoules each containing 1 ml.Seven laboratories collaborated in assaying its potency in terms of the Fourth International Standard by the intravenous inoculation of mice. The geometric mean value, taking the results of all the laboratories, was 270 International Units per ampoule and the maximum variation between laboratories was 15%.In vitro (lecithinase) tests were also done by three laboratories, giving an average of 261 International Units per ampoule.The dry weight contents of ampoules, determined in three laboratories, varied by less than 3%, with an average of 90.35 mg per ampoule.The standard was stable for 120 hours at 56 degrees C.Each ampoule of the Fifth International Standard for Gas-Gangrene Antitoxin (Perfringens) contains 270 International Units, and one International Unit is contained in 0.3346 mg of the International Standard.

Animals↗
PubMed1962

An international collaborative study of the assay of the potency of poliomyelitis sera.

As a first step towards the standardization of poliomyelitis vaccine, the neutralizing antibody titres of ten test antipoliomyelitis sera were measured in nine laboratories in different countries in comparison with a reference preparation. A standard neutralization test was not used by all laboratories and in general those neutralizing the serum-virus mixtures at a temperature of 37 degrees C obtained higher titres than those laboratories using lower temperatures. When the potencies of the test sera were calculated, in terms of the reference preparation, there was good agreement by all laboratories with sera of similar neutralizing capacity. The reference sera used in this study have proved useful for obtaining relative potencies for poliomyelitis sera of different neutralizing capacity and of different origin. These potencies have been shown to vary much less from one laboratory to another than did the uncorrected titres.For technical reasons, these reference preparations are not considered ideal for international standard preparations, and new sera have been prepared for this purpose.

Biological Assay↗