Preparing plant root tip cells for microscopical examination.

Abstract

The technics generally used for preparing root tip cells for microscopical examination destroy mitochondria and other cytoplasmic particles and remove lipoidal material. Fixation in a bichromate solution followed by treatment with osmic acid preserves these granules through normal embedding procedures (cf. Zirkle, 1929; Newcomer, 1940); also fixation in neutral formalin and embedding in the water-soluble wax, Aquax, may completely preserve lipoidal matter, and thus the mitochondria. The separation of cells in squash preparations usually entails acid hydrolysis of the intercellular cement. Treatment for one hour with a 5% solution of a commercial pectinase powder in a 1% aqueous solution of peptone allows good separation of cells of bean root tips fixed in acetic-alcohol. By this method it has been demonstrated that the Feulgen hydrolysis removes cytoplasmic and nucleolar RNA. To preserve the mitochondria it is advisable to immerse the bean roots in a 5% aqueous solution of polyvinyl alcohol for 24 hours a...