Improved method for chick whole-embryo culture using a filter paper carrier

TLDR

The EC method improves upon New’s 1955 glass‑ring technique for chick embryo culture. The authors aim to provide a versatile EC culture system that enables microsurgery, grafting, bead implantation, microinjection, electroporation, and discuss alternative setups. EC culture uses a filter paper carrier to tension the blastoderm and vitelline membranes while the embryo develops on an agar‑albumen substrate. EC culture allows rapid, efficient culture of embryos from pre‑primitive streak to stage 10, permitting dorsal‑side‑up or ventral‑side‑up orientation from stage 8 onward, while younger embryos remain ventral‑side‑up.

Abstract

We describe a simple method of chick whole-embryo culture, which uses a filter paper carrier to hold the early blastoderm and vitelline membranes under tension while the embryo grows on a substratum of agar-albumen. This is a quick and efficient means of setting up cultures of chick embryos beginning at pre-primitive streak stages to stage 10 (stages X--XIV, Eyal-Giladi and Kochav [1976] Dev Biol 49:321-337; stages 1--10, Hamburger and Hamilton [1951] J Morphol 88:49--92). This is an improvement on the original method of New, which used a glass ring and watch glass (New [1955] Exp Morphol 3:320--331). Our modification of New's method, which we call EC (Early Chick, pronounced EASY) culture, facilitates several manipulations in early chick embryos, including microsurgery, grafting, bead implantation, microinjection, and electroporation. Using the EC method, embryos at stage 8 and older can be readily cultured either dorsal-side up (in contrast to New's method) or ventral-side up, as desired; embryos younger than stage 8 can be culture only ventral-side up (as with New's method). We also discuss some alternative methods for setting up these cultures.