LESSON II 



Types of Micro-organisms Microscopic Examination of Bacteria, 

 stained and unstained Staining of Micro-organisms with Simple 

 Basic Aniline Dyes Preparation of Cover-glass Films. 



Types of Micro-organisms 



EXAMINE microscopically the broth cultures supplied. 

 Cultures supplied 



1. Streptococcus pyogenes. 



2. Staphylococcus pyogenes aureus. 



3. Bacillus filamentosus. 



4. Torula alba. 



5. Sarcina lutea. 



(a) Clean a cover-glass (No. 1, f in. by f in.) with alcohol, 

 and pass it through the flame in order to sterilise it. 



(b) Under aseptic precautions with a platinum loop 

 remove a drop of the culture and place it on the centre of 

 the cover-glass. 



(c) Gently press the cover-glass on a clean slide and 

 examine the specimen with a -^ in. oil immersion, using a 

 narrow diaphragm and the concave mirror. 



Make sketches of the various specimens. 



