I really appreciate any help I can get - experienced answers only please!
OK here is the deal - my lab professor mixed two bacteria in a broth tube, one is gram negative, one is gram positive. Before running tests on the two separate bacteria, I need to isolate them into an "Uknown A" and a "Unknown B" - after they are isolated we are then supposed to take the isolated bacteria and put each in a agar slant tube.
The first day of this project I put my sterilized loop in the broth - and then did a streak plate on each of the following agar dishes: mannitol salt, EMB, and TSA. I then put them in the incubator - on Wednesday I returned to lab, the results were:
TSA Plate - growth, white colonies, also 2 yellow dots (is this contamination?)
Mannitol Salt Plate - NO GROWTH
EMB Plate - growth
*** EMB plates only grow gram negative, I did a gram stain to ensure that this bacteria culture was pure and it seems to be pure (is this correct?)
*** Then I made a agar slant tube of my gram negative bacteria, assuming this is pure.
How do I isolate my gram positive? Do I just get this off the TSA plate and double check its gram positive?
PLEASE HELP!
Thank You
