The effects of storage on the retention of enzyme activity in cryostat sections. A quantitative histochemical study on rat liver.
The effect of storage of unfixed cryostat sections from rat liver for 4 h, 24 h, 3 days and 7 days at -25 degrees C was studied on the activities of lactate dehydrogenase, glucose-6-phosphate dehydrogenase, xanthine oxidoreductase, glutamate dehydrogenase, succinate dehydrogenase (all demonstrated with tetrazolium salt procedures), glucose-6-phosphatase (cerium-diaminobenzidine method), 5'-nucleotidase (lead salt method), dipeptidyl peptidase II, acid phosphatase (both simultaneous azo coupling methods), D-amino acid oxidase (cerium-diaminobenzidine-cobalt-hydrogen peroxide procedure) and catalase (diaminobenzidine method). The effect of drying of the cryostat sections at room temperature for 5 and 60 min was investigated as well. The enzyme activities were quantified by cytophotometric measurements of test and control reactions. The test minus control reaction was taken as a measure for specific enzyme activity. It was found that the activities of all the enzymes investigated, with one exception, were affected neither by storage of the cryostat sections at -25 degrees C for up to 7 days, nor by drying of the sections at room temperature for up to 60 min. The exception was xanthine oxidoreductase, whose activity was reduced by 20% after 5 min drying of sections or after 4 h storage. Therefore, only incubations for xanthine oxidoreductase activity have to be performed immediately after cutting cryostat sections, whereas for the other enzymes a considerable margin appears to exist.
Frederiks
W M
WM
Laboratory of Cell Biology and Histology, Academic Medical Centre, Amsterdam, The Netherlands.
Ouwerkerk
I J
IJ
Bosch
K S
KS
Marx
F
F
Kooij
A
A
Van Noorden
C J
CJ
D000818:Animals; D016616:Cryoultramicrotomy; D006651:Histocytochemistry; D008099:Liver / Q000201:enzymology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013048:Specimen Handling; D016707:Tissue Fixation