I did an experiment with tryptic soy agar medium recently and I had some issues so I need a few questions answered. The experiment was to use a TSA plate and first streak for isolation with yogurt in order to get a culture of Lactobacillus or Streptococcus. After incubating the first plate, we were asked to transfer 8 loopfuls to a second TSA plate. Next, we were asked to put a chloramphenicol disc in the center, a drop of isopropyl alcohol at the top, drop of milk at the bottom, bleach on the left, and finally hand sanitizer on the right. Because the plates had to be stored upside down, my chloramphenicol disc fell out. At some point, the chloramphenicol disc got stuck in the exact spot as the hand sanitizer. Now I don't know which one of those two things inhibited growth of the Lactobacillus/streptococcus. I later used sterilized forceps to remove the disc and re-insert it into the center, but I have no way of knowing if it ended affected to right side before it was removed.
So, in short, I need to know if hand sanitizer and chloramphenicol will both inhibit growth of those species or if only one or the other will. I will do some online research as well but I would like to verify what I find because there are often mixed and confusing answers online.
Thanks! :-)
(also, I'm curious what affect chloramphenicol, milk, bleach, rubbing alcohol, and hand sanitizer will have on Saccharomyces cerevisiae and on Lactobacillus/Streptococcus thermopilus found in yogurt)?? They appear to have no affect on the yeast thus far but I'm unsure of my skills so I don't know how well I performed the labs.
Quick Reply
