Quantitative Determination of Phosphatase Activity in Chick Embryo Duodenum cultured in Fluid Media with and without Hydrocortisone

Abstract

DIFFERENTIATION and phosphatase accumulation in the intestinal epithelium of the sixteen-day chick embryo cultured in vitro were accelerated by the addition of hydrocortisone to the nutritive medium¹. When an attempt was made to culture relatively large pieces of duodenum, in order to determine phosphatase content quantitatively, it was found that the best survival and differentiation were obtained in those specimens that liquefied the plasma clot on which they were placed; such free-floating pieces maintained a normal surface configuration without any tendency to form the elaborate outgrowths that develop when a solid substrate is present. This observation has now led to the finding that as much as 25 mgm. of embryonio duodenum may be successfully cultured in 2 ml. of fluid, in a 25-ml. Erlenmeyer flask.