introduction 3 1 



Quantitative and Qualitative Determinations of Organisms 

 IN Foods and Drugs 



Substances to be analyzed. 

 Liqiiids of all kinds. 



Semiliquids and semisolids miscible with water. 

 Solids of all kinds. 

 Numerical and quantitative limits of contamination in different 

 substances. 

 For molds — quantity of spores and hyphae. 

 For yeasts — number and kind. 

 For bacteria — number and kind. 

 For pus, dirt, sand, etc. 

 Methods. 



Making concentrations. 



Making dilutions. 



Making the counts and estimates. 



Bacteria. 



Yeasts. 



Mold spores and mold hyphae. 



Algae, in drinking waters, etc. 



Protozoa. 



Pus cells, in milk, etc. 



Dirt, sand, etc. 

 Plate counts — Petri dish cultures. 



Culture media used. 



Optimum temperature. 



Time of incubation. 

 Qualitative determinations. 

 Apparatus. 

 Culture media. 

 Stains. 

 Special methods. 



Colon group of bacilli. 



Presumptive colon bacillus test. 



Sewage streptococci. 



Dysentery bacilli and amebae. 



Bacillus typhosus. 



Paratyphoid group. 



Cholera vibrio. 



Yeasts. 



Molds. 



Animal parasites. 



Larvae, ovae, etc. 



