CHAPTER VI 

 BACTERIOLOGICAL TECHNIC 



As may readily be supposed, the minuteness and wide distribution of 

 microbes call for special methods of study and examination. Even the 

 largest forms are far below the ken of unaided vision. Their general dis- 

 semination through organic substances calls for special methods for the 

 separation and isolation of individuals or single bacterial cells. The 

 difficulties of some phases of laboratory technic are further increased by 

 the resistance of spores to various agents and substances which are readily 

 fatal to higher organisms. The methods of examination are also greatly 

 complicated by the marked polymorphism of many species. 



Bacteriological technic comprises the use of glassware, compound 

 microscope, and other apparatus, a thorough knowledge of sterilization and 

 disinfection, the preparation and use of culture media, the making of micro- 



Pic, ii. a, Nest of beakers and reagent bottler. The smaller and medium size 

 beakers are more desirable for bacteriological work. The reagent bottles are for Canada 

 balsam, stains, clearing fluid, etc. 



bic cultures, and the study of cultures. Methods vary greatly. The 

 following represents a brief summary of general methods which are noted 

 for simplicity and which have proven very satisfactory after years of 

 testing. 



i. Cleaning the Glassware 



All glassware, such as test-tubes, flasks, beakers, Petri dishes, pipettes, 

 shells, bottles, etc., which is to be used in bacteriological work must be clean; 

 that is, free from all extraneous organic as well as inorganic matter. To 

 accomplish this, it is necessary to use an abundance of pure water, hot as 

 well as cold, aided by sand, paper shreds, brushes, towels, alcohol, acids, 

 soap, sodic and potassic hydroxides, and whatever else may be necessary. 

 Boil, wash, rinse, and wipe within and without repeatedly until it looks, 



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