SECTION III 



COLLECTION AND EXAMINATION OF CERTAIN 

 MORBID MATERIALS 



THE COLLECTION AND EXAMINATION OF PUS 



When a simple microscopical examination has to be made, the 

 collection of pus presents no difficulties, as the few bacteria 

 which may gain access from the skin or the air will not lead to 

 error. The case is otherwise where cultural examinations have 

 to be made, or where the material has to be taken to a laboratory. 

 Here the material should be collected in a pipette. The best 

 form to use is the "opsonin" pipette (see p. 171), plugged with 

 cotton-wool at the wider end. It may be sterilized by dry air, or 

 more simply by passing it through the flame several times, 

 taking care to make each part very hot, but not hot enough to 

 melt the glass. 



When the abscess has been opened, a considerable quantity of 

 pus should be allowed to flow out, and the sterilized pipette is 

 then to be passed through the incision (care being taken to avoid 

 contact with its sides) and the pus carefully sucked up into the 

 bulb, using an indiarubber nipple. The fluid thus obtained may 

 be used to inoculate cultures there and then, or both ends of the 

 pipette may be sealed in the flame. 



The Examination of Pus. 



The organisms which may cause pus are extremely numerous, 

 the most important being streptococci, staphylococci, the pneumo- 

 coccus and the gonococcus, the bacilli of typhoid fever, tubercu- 

 losis, and glanders, the B. coli communis, the B. pyocyaneus (the 

 organism which produces blue pus), and the fungus of actino- 

 mycosis. In the majority of cases the organism which is present 

 in a given sample of pus can be determined by a microscopic 



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