We use Rodac (contact) plates for our environmental monitoring. Is there a
method to estimate TNTC plates? How do you read spreader colonies on a
contact plate? Is there a standard method for counting colonies on a Rodac
On 2009-10-05 11:41:10 -0400, "Cherie Parker"
<[Only registered users see links. ]> said:
I thought contact plates went out with bleeding times. I don't think
there are any clear meaninful guidelines for how to quantify plates.
What may be an acceptable count now may be TNTC in a few hours. The
environment is rather dirty so what is the purpose? To try to educate
someone on how to clean? It might be more important to examine what
cleaning solutions they are using. Most cleaning crews I've run into
seem to make the strongest formula they can instead of going by the
manufacturers directions. How many times have you walked into a public
bathroom and been assaulted by the fumes of the disinfectant? If a
solution works best at 2% it doesn't work better at 10 or 20%, but look
at what they are doing. Even in our lab, most of our bleach solutions
were much more than the 5% recommended. After washing a bench down, it
sometimes smelled like an over chlorinated pool!
We stopped doing any environmental cultures because no one could
John Gentile MS, M(ASCP)
Laboratory Information Mgr.
VA Medical Center
Providence, RI [Only registered users see links. ]