The Use of Enzymes in the Preparation of Root-Tip Smears

Abstract

A simple root-tip smear method for the study of somatic chromosomes of Allium is descr., in which an aqueous soln. of colchicine and Pectinol, (an enzyme prepn.) is used. The root tips are placed in a 0.2% aqueous colchicine soln. for 30 min., fixed in propionic-alcohol soln., run through a graded series of alcohols, washed thoroughly, treated with a 1% aqueous soln. of Pectinol for 1 to l1/2 hrs., and allowed to stand in water 3-5 days to soften. A thin transverse sec-tion thru the meristematic portion of the root tip is then smeared on a slide in a drop of propiono-carmine stain in the usual way and sealed.