This experiment allows you to observe the development of a chick embryo outside its shell. Cultured chicks are also more accessible for manipulation. Compare the extent of bone mineralization of control chicks to those in shell-less culture to determine if the egg shell provides a source of calcium.
Shell-less culture set up at 3 days of incubation
1. Squirt section of PVC pipe with 70% ethanol and allow to dry in laminar flow hood. Label.
2. Create cradle with generic plastic wrap; be careful not to touch middle.
Secure with rubber band. Cover with lid of sterile petri plate.
3. Wipe 3-day egg with 70% ethanol.
Allow to sit on side in 37º C incubator for 5-10 minutes to allow embryo to rotate to top side.
4. Remove lid from cradle, leave in hood. Crack lower side on edge of finger bowl.
Resolutely open into cradle. Cover with lid and return to 37ºC incubator. The embryo will float to the
surface. Obviously the embryo will develop best if the yolk is not broken. Warm, incubated
eggs break more easily than refrigerated ones, unfortunately, but embryos will usually
survive for a while if there are only small tears in the yolk.
5. Observe periodically to watch organ development and extra embryonic membrane formation.
Do not keep outside the incubator for more than 5 minutes.
Remove dead embryos promptly to freezer.
Examine the survivors after one week and compare them to control embryos incubated in the shell.
Chick embryo cultured for 2 days
RESULTS
Although many embryos died, some chicks lived in shell-less culture for 16 days. Cultured chicks were smaller than comparably aged chicks incubated in the shell.
|
|
首页
