On this page is a set of general review questions for which
there is presently no posted key. 1. Relevant to just plain, old
Common Sense: Technicians A and B work in a water quality lab.
They received a sample of water from the Vilas Park Beach and
they found that they were out of sterile saline which they
usually use for a diluent, so they used the next best thing on
hand: sterile Brain Heart Infusion Broth. Technician A made
decimal (1/10) dilutions of the water sample and then inoculated
plates from the dilutions. Technician B did the same, but he got
distracted and let his first 1/10 dilution sit around for a few
hours before making subsequent dilutions and platings. After
incubation of the plates, Technician A got a count of 4.4 X 102
CFU/ml and Technician B's count was 4.9 X 106 CFU/ml. Who had
the more reliable count of the water sample? Why? (Note: Both
technicians performed specific techniques regarding dilutions,
inoculations and incubations correctly. The answer has nothing
to do with those techni