Angeline,

You are right in "window time" for BrdU. The drug half
life is about an hour(It is a chemotherapeutic agent
for Ca cheek). Roughly, all cells that are in the
S-phase of the cell cycle during that one hour should
would be having BrdU in its nucleus. If you are
interested in marking the whole population of newly
formed during a time span then repeated pulses of BrdU
has to be administered. The dosage is critical as an
excess would kill the cell (Thats what it is intended
for) while a very small amount might not be detected
immunohistochemically.Dose that is generally used in
studies on rodents, when administered
intra-peritoneally is 50mg/ kg body weight. 
Hope it would be useful.In case you need ref for any
of these, please feel free to mail.I do not have them
with me at hand.
 
    
--- "J. A. Kiernan" <jkiernan@uwo.ca> wrote:
> Your email was addressed to me alone, and I cannot
> give you any useful suggestions.
> 
> For expert advice you should address your question
> to the
> HistoNet listserver. Your email indicates that you
> subscribe
> to that listserver. Probably someone looking at
> today's 
> Histonet questions will be able to help you. I do
> not know
> the answer to your question, and I do not intend to
> go to
> the library and occupy an hour looking it up. 
> 
> Histonet is a useful resource for everyone in the
> field, 
> especially those who do not have a library or a
> shelf of 
> textbooks. Anyone can answer a question. All can
> read
> the answer, and some will make comments that
> support,
> supplement, modify, contradict etc. Questions and
> replies
> are sent to everyone. Anyone can chip in with an
> answer
> or a suggestion. You will learn more from this than 
> from picking out a regular answerer (me, about whom
> you
> obviously know nothing) to ask a question that might
> interest many other Histonetters. 
>  
> I'm forwarding this reply to Histonet at large
> because
>  (a) it's of geenral interest, and
>  (b) someone reading it might effortlessly be able
> to 
>      give you an answer to your question.
> 
> John Kiernan
> London, Canada. 
>    kiernan@uwo.ca
>    http://publish.uwo.ca/~jkiernan
> -----------------------------
> On Tue, 3 Jul 2001, Angeline Martin-Studdard wrote:
> > Date: Tue, 03 Jul 2001 16:07:48 -0400
> > 
> > Dear Dr. Kiernan,
> > 
> > My name is Angeline Martin and I am employed at
> the Medical College of Georgia.  I have had the
> pleasure of reading and utilizing your advice
> provided on the histonet many times.  Our projects
> have involved the use of BrdU and I have been unable
> to obtain clarification on precisely how long this
> will be expressed in cells.  We inject BrdU (IP)
> into young mice who have undergone some level of
> ischemia.  The BrdU is easily detectable in the
> brain tissue sections.  However, my concern is
> whether we are observing all new cell development
> from injection up until the time of sacrifice or is
> there only a "window" of opportunity for each cell
> in which the BrdU will be detectable?
> > 
> > Any help you can provide will be greatly
> appreciated.
> > 
> > Sincerely,
> > 
> > Angeline M. Martin
> > Department of Neurology
> > Medical College of Georgia
> > 1459 Laney-Walker Blvd.
> > Augusta, GA 30912
> > Ph: 706-721-6969
> > Fax: 706-721-6839
> > Amartin@mail.mcg.edu
> > 
> ----------------------------------------
> 
> 


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