What are the most likely point in nutrient media preparation

What are the most likely point in nutrient media preparation or later at which contamination may be introduced? What signs would indicate contamination? What is the source of the following elements in nutrient media prepared? (See Medium Recipes pg.20 of Microbiology Laboratory Theory & Applications) Carbon? Nitrogen? What are the two types of nutrient media prepared in BIQL3200L?

Solution

Most likely points of contamination introduction in nutrient media

Signs of contamination.

Since the media contents are not provided in the question , I will give you the general sources.

Sources of Carbon is the Glucose, glycerol, tryptone soy, casein soy digest, beef extract, potato dextrose…etc

Sources of Nitrogen is Yeast extract, NH4Cl, Beef extract..etc