[Fixation of enzymes in freeze-dried tissue with gases]

Several gaseous substances were tested for fixation of enzymes in frozen dried cryostat sections. Formaldehyde, glutardialdehyde and phtaldialdehyde vapours are effective in stabilizing lysosomal hydrolyse, so improving their orthotopic localization. Glutardialdehyde and glyoxylic acid vapours are useful fixatives for dehydrogenase histochemistry in frozen dried cryostat sections. Heating of sections alone has no fixating effect on enzymes at all.