Maybe your hydrometer is reading incorrectly. Try putting a damp gauze in a
plastic sandwich bag with the plate. That will add the humidity and the
"wind" from the circulating fan won't dry out the agar.
--
John Gentile Rhode Island Apple Group
yjgent at home.com Past President, Publicity Chairman
"I never make mistakes, I only have unexpected learning opportunities"
> From: nmaccallister at webtv.net (Neil MacCallister)
> Organization: WebTV Subscriber
> Newsgroups: bionet.microbiology
> Date: Wed, 3 Jan 2001 02:06:56 -0800 (PST)
> Subject: 32* incubator humidity?
>> Good setpoint for doing Aerobic Plate Counts ,,(as per USP-24 <61> for
> example)?
> -----------------------------
> "I don"t want the plates to dry in 48 hrs (they were at the ambient
> 32%),..nor the agars/cfu's to drown in condensate. I've bumped it up to
> 75% from a suppliers recommended 40-60%..
> .(they were still drying). Why not 85? No condensate is forming
> inside the incubator,..it is well insulated. I am using commercially
> prepared (Letheen) agar plates, used before their expiration date. The
> agars were kept sealed and refrigerated before use.
>
