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Pulverized diatomaceous earth used as an agent for the filtration of bacteria from water and sewage. The earth suspension rests on a wire micro-mesh base in a funnel, and after filtration is added to suitable enrichment media for the isolation of faecal pathogens.  

Production of H2S gas on culture is a differential characteristic with organisms such as the enterobacteria. Brucella and Clostridia. Positivity is indicated by the blackening of lead acetate test papers suspended in the neck of the culture tube, or blackening of agar or gelatin media which incorporate ferrous salts.  

Used for glass, metal and paper articles in the laboratory, and for powders, fats and oils pharmaceutically. Penetration of hot air is slow, and a fan is necessary to maintain an even temperature in all parts of the load. The process is divided into three periods: (1) heating up period (about 1 hour for an…

The original culture of a described bacteriological species (deposited in a national collection of type cultures).  

Antibodies reacting with an antigen which has no biological relationship to the immunizing stimulus.  

Semi-synthetic penicillin possessing very similar properties to ampicillin, to which it hydrolyses in solution and in vivo.  

Micro-filter consisting of a metal holder for a membrane or asbestos pad filter, with a 5 cm³ (bijou) vital screwed at each end. The assembled apparatus is centrifuged, forcing fluid from one vial through the filter into the receptor vial.  

Cell counting chamber for the enumeration of bacteria, consisting of a thick microscope slide with a depressed platform 0.02 mm lower than the top surface, ruled with Thoma ruling—i.e., a 1 mm square subdivided into 400 squares each 1/20 x 1/20 mm (0.0025 mm² area). With the special coverslip in position 0.02 mm above this…

A classification of the cholera vibrios into 6 groups by their production of acid from mannose, sucrose and arabinose. Group 1 (mannose and sucrose positive) contains the classical pathogenic vibrios.  

Microscopical examination of bacteria—especially for motility—by observing the organisms in a drop of culture fluid hanging from the underside of a coverslip. The drop is kept from contact with the carrying slide by a cavity in the thickness of the latter, or by separating a plain slide from the coverslip by small portions of plasticene.…