Part a. Two plates received 100 L from the same dilution tube. The first plate had 293 colonies, whereas the second had 158 colonies. Suggest

Part a. Two plates received 100 µL from the same dilution tube. The first plate had 293 colonies, whereas the second had 158 colonies. Suggest reasonable sources of error.

Part b. Two parallel dilution series were made form the same original sample. The plates with sample volumes of 10^-5 mL from each dilution series yielded 144 and 93 colonies. Suggest reasonable sources of error.

Part c. What are the only circumstances that would correctly produce countable plates from two different dilutions?