The quantification of ormazans in tissue sections by microdensitometry. III. The effect of objective power and scanning spot size.

In this article, it is reported that the formazans derived from neotetrazolium chloride (NT) and 2-(2-benzothiazolyl)-3-(4-phthalhydrazidyl)-5-styryl-tetrazolium chloride (BPST) can be measured by microdensitometry of tissue sections with a wide range of scanning spot sizes, without any significant effect on the recorded extinctions. The spot sizes tested ranged from 0.20 to 16 mum. Thus when large fields have to be measured, it is possible to use low-power objectives and still obtain valid results.