Jacklyn Hodges writes,
<When Difco and BBL merged, things have not been the same with the media.>
I did know they had merged, but I don't recall when. For awhile, I was
out of the media prep business, and then when I got back to doing it -
December 1999 through Sept. 2000 - I noticed certain things, at least
with TSB and lactose broth. Namely, that sometimes I would make a batch
and the stuff wouldn't dissolve; despite being warmed and constantly
stirred on a magnetic hotplate, it would be cloudy - never mind cloudy,
*opaque* would be a better word for it. Then even when the media *looked*
right, most of the time the pH would be off, and I mean *off*! Such as
6.3 or 6.4 for TSB (which is supposed to be 7.3 +/- 0.2) and 6.0 or 6.1
for lactose (which is supposed to be 6.9 +/- 0.2). The agar was better, I
didn't have problems with that, but that broth sure threw me, and I
couldn't understand it because I'd been making Difco media on and off
since 1992. This post of yours, Jaclyn, suddenly made me think of my
fairly recent problems with Difco media; that on top of a serious problem
getting hold of 1% chapman tellurite solution to use in making VJ agar,
which happened during the summer of 2000. So when exactly, did this merge
take place, and is it possible that my own aforementioned problems were
the result of that?
Infectionately,
Yersinia.
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