6-TG/HPRT

[Sabine Hanelt]

Hi netters,
in our group we are working with the hprt mutation assay and the BrdU assay to 
detect HPRT deficient clones.
Since some weeks we have a never ending discussion about two things. 
The first is: what does 6-TG (thioguanine) exactly do so that hprt proficient 
cells die. Does the polymerization stop or are the enzymes not able to 
translate mRNA with 6-TG into functional proteins, or both of it.
The second is: for the BrdU assay we use 6-TG in much higher concentrations 
(34 µg/ml) than used in the "classical" hprt assay (2-10 µg/ml). Does 6-TG 
bloc the growth of the cells when it is used in higher concentrations and if 
this is the case, in which form does it bloc.
Thank's for your help
Sabine