I would agree w/ Beat.  I would consider concentrations above 5µg/ml a
terminal but not fatal staining concentration.  At 5µg/ml hepatocytes can be
monitored temporally for 8 hours w/o deleterious effects from the dye.  

Ramin Rahbari
PARKE-DAVIS Pharmaceutical Research
Worldwide Preclinical Safety
2800 Plymouth Road
Ann Arbor,  MI  48105
Voice         (734) 622-3383
Fax           (734) 622-5001
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-----Original Message-----
From: Beat Ludin [mailto:[log in to unmask]]
Sent: Sunday, March 19, 2000 6:33 PM
To: [log in to unmask]
Subject: Re: Visible DNA Stain, Hoechts or DAPI?


I've been using Hoechst 33342 at 100-200ng/ml. In my tests, this
concentration did not noticeably impair growth of mammalian
fibroblastic and epithelial cell lines over a period of 4 days.
(5-10ug/ml of as proposed by Ramin will act as a mitotic blocker as
far as I remember. I didn't do the experiment myself, though, and I
don't remember the reference).

Cheers,

        Beat


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