To best measure cell proliferation in samples from the intestine.

Arrangement of the intestinal cell lining, as it is, into distinct anatomically defined zones where proliferation is confined to the crypts, makes it an ideal tissue to study growth control mechanisms. While many methods have been used to quantify cell proliferation in the gut, several of them have severe limitations and others (although potentially better) have been misused and misinterpreted. Here, correct use and interpretation of labelling studies will be described as will a well established alternative method that provides equivalent results for one-sixth of the effort.