Principles of Genetics and Breeding

Chromosome preparation from embryos

1. Take 1ml of colchicine and add 20 ml of hatchery water.

2. Add the required number (3-4) of embryos to the colchicine solution and leave for a minimum period of 4 hrs.

3. Drain off the colchicine and add 0.7% Na Cl.

4. Remove yolk sac from the embryos and put into distilled water for 20 min. This will swell embryonic cells.

5. Transfer the embryos into an ethanol/acetic acid 4;1 mixture. They can be stored for up to 30 days at 4ºC.

6. Mince the embryos for 1 min with glass rod or scraped using fine forceps to dissociate epithelial cells.

7. Drop the solution into the prewarmed slide (45ºC).

8. Leave for 10 sec.

9. Stain the slide in 5% Giemsa stain for 30 min and wash the slide in tap water.

10. Dry the slide and observe under the light microscope.