The Action of Pectinase Solutions on Sections of Acetone-fixed Human Tissues: A Preliminary Note

Abstract

Thin pieces of tissue fixed in ice-cold acetone, imbedded in paraffin, sectioned at 4-6[mu], mounted on slides, deparaffinized and brought to water through graded alcohols are incubated for 48 hrs. at 37oC in 0.4% solns. of pectinase, pectin esterase, pectinol-O, polygalacturonase, or beta-glucuronidase. Following enzyme treatment, washed slides are stained with hemotoxylin and eosin, orcein stain for elastic tissue, or periodic acid Schiff''s reagent (PAS). There is a loss of PAS-positive materials, mucin, glycogen, reticulin, ground substance of cartilage, etc. in treatment with pectinase; polygalacturonase removes about the same amt. of material as pectinase; with pectinol-O the removal is not so complete, but is qualitatively the same as with pectinase; pectin esterase does not remove PAS-positive material, but rather enhances the coloration; and beta-glucuronidase apparently has no effect. The removal of PAS-positive material by pectinase, and especially by polygalacturonase, is evidence that this material is probably carbohydrate.