title: Freeze substituted tissue in 5'-nucleotidase histochemistry. Comparative histochemical and biochemical investigations.
abstract: The suitability of freeze-substitution in n-butanol and paraffin embedding of tissues for the histochemical demonstration of 5'-nucleotidase was investigated and compared with commonly used preparation techniques, such as fresh frozen sections and cryostate sections of cold formalin and glutaraldehyde-fixed rat liver. The influences of each step of the preparation techniques on the enzyme activity were controlled by a quantitative radiochemical assay. Freeze substitution was revealed to be superior to the commonly used preparation techniques with respect to: 1) high sensitivity and specificity of the histochemical 5'-nucleotidase reaction (this is based on the fact that incubation media with very low lead concentrations (0,6 mM/1) can be used); 2) excellent morphological appearance of the tissues showing cytological details of enzyme localization; 3) unlimited storage of the tissue materials and ease of sectioning.
mesh_terms: D000818:Animals; D000440:Butanols; D002467:Cell Nucleus / Q000201:enzymology; D002940:Circadian Rhythm; D005260:Female; D005615:Freezing; D006651:Histocytochemistry / Q000379:methods*; D007854:Lead / Q000494:pharmacology; D008099:Liver / Q000201:enzymology* / Q000648:ultrastructure; D009708:Nucleotidases / Q000378:metabolism*; D009940:Organoids / Q000201:enzymology; D011309:Preservation, Biological; D051381:Rats
chemical_list: D000440:Butanols; D007854:Lead; D009708:Nucleotidases