counting cell divisions in vivo
oliver at nasw.org
Thu Feb 4 16:59:38 EST 1999
Thanks for the info! But you're killing me: What do they find with the
BrDu and radio incorporation assays?
(p.s. Since asking my question, I've noticed that Hayflick himself
doesn't think the Hayflick Limit is the explanation for aging--though
perhaps he thinks it is respeonsible for a rarely achieved ceiling age
[haven't gotten that far in his book])
Doug Hosack wrote:
> There are several methods currently used to study cell division in vivo:
> Of recent interest is the study of telomere lengths, but this is confounded
> by telomere-lengthening by telomerase such as found in hematopoetic cells.
> Some researchers have tried to address this problem with telomerase assays,
> but these assays only measure the amounts of telomerase present. That is to
> say that they do not necessarily measure telomerase activity in situ.
> (There are other factors such as TRF1 and Tankyrase that regulate whether
> the telomerase present actually lengthens telomeres.)
> Other methods involve measuring the incorporation of labeled nucleotides
> into DNA, such as radionucleotides, BrdU or deuterated nucleotides. For
> long-term studies, a researcher would first load the animal with the label,
> and then measure the loss of label at various timepoints as a measure of
> cell replication.
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