Research in Cystic Fibrosis

Abstract

(Second of Three Parts)Tissue-Culture StudiesMetachromasiaThe earliest observations of differences between cystic-fibrosis and normal cells were made by Danes and Bearn,⁵⁴ who noted metachromasia, a staining property produced by interaction of a cationic dye with negatively charged macromolecules, in most lines of heterozygote and homozygote fibroblasts, but only rarely in normal fibroblasts. They distinguished two morphologic types and, in addition, a small group of families with cystic fibrosis whose cells are ametachromatic. All these various types "breed true."¹⁵ These findings provided the first objective suggestion that phenotypically similar patients might, in fact, be genetically heterogenous. However, these authors . . .