LAB 8 OBJECTIVES

 

1)    Cultivating microbes (part 2).  Know the steps involved in preparing sterile nutrient broth tubes and nutrient agar deep tubes, slant tubes, and plates.  Be familiar with the general maintenance, incubation, and preservation of stock cultures and working cultures.  

 

2) Be able to calculate population counts from nutrient broth cultures of bacteria (E. coli) and from a food sample.  Be familiar with all the procedures and materials used to perform quantitative plating (standard plate count).

 

Methods include:

a.     knowing how to properly use and handle dilution pipettes

b.    knowing how to prepare blanks of known dilutions

c.     knowing how to properly prepare plates using melted nutrient agar pours

d.    knowing how to use a Quebec colony counter

e.    knowing how to mathematically calculate the number of colony forming units (CFUs) per milliliter from a bacterial culture or number of CFU’s per gram from a food sample.