Approx. 2 day embryo (or approx. Hamburger and Hamilton stage 11). Stained.
Approx. 3 day embryo (or approx. Hamburger and Hamilton stage 17+).
Approx. 4 day embryo (or approx. Hamburger and Hamilton stage 21 or 22)
Approx. 5 day embryo (or approx. Hamburger and Hamilton stage 24 or 25)