Preparation of Cell-free Plasma Coagulase of Staphylococcus aureus

Abstract

IN 1908, Much reported that certain strains of Staphylococcus had the property of coagulating oxalated or citrated human blood plasma. This is nowadays considered as one of the most characteristic features of pathogenic Staphylococcus aureus, and is used to differentiate it from various other cocci. To my knowledge, attempts to separate the plasma coagulase from the bacterial cells have so far failed; for example, in personal experiments by filtration of broth cultures through Seitz and Chamber-land filters, separation of cells by the centrifuge, killing the staphylococci by heat or the vapour of ether or chloroform.