MANIPULATION OF EGGS 



Microscopy 



Suitable fluid media for the recovery and handling ofliving eggs 

 for microscopical examination are blood serum, 0-9 per cent sodium- 

 chloride solution and a number of buffered isosmotic saline solutions, 

 such as Tyrode's, Locke's, Simm's, Gey's and Hank's solutions. 

 Eggs deteriorate less rapidly in vitro when suspended in media 

 containing substances of high molecular weight, and accordingly the 

 saline solutions mentioned are improved by the addition of materials 

 such as hen-egg albumen and crystalline bovine serum albumen. 



Follicular oocytes can be obtained by placing the ovary in a fluid 

 medium in a suitable container, incising the follicle wall and teasing 

 out the contents (small ovaries) or flushing out the contents with 

 the fluid (large ovaries). Ovulated oocytes and eggs undergoing 

 fertilization or cleavage are recovered by somewhat different 

 methods according to the animal involved. From the rabbit 

 Fallopian tube, eggs are best obtained by flushing. The tube is 

 removed from the abdomen by transecting the uterus about half an 

 inch from the utero-tubal junction and cutting through the fat and 

 other tubal adnexae, with care to avoid nicking the tube. The 

 specimen is placed on a cork pad and the tube trimmed of most of 

 the adherent tissue so that it can be straightened out. The attached 

 portion of the uterus is cut away to reveal the uterine opening of 

 the tube. A finely-drawn Pasteur pipette with a capillary having an 

 external diameter of about 0-5 mm is charged with the flushing 

 solution and inserted into the isthmus of the tube through the 

 uterine opening. The Fallopian tube is held vertically above a 

 suitable receptacle such as a glass cavity-block or watch-glass and 

 the solution propelled through it so as to wash the eggs into the 

 receptacle. Essentially the same method can be used for the Fallopian 

 tubes of the domestic animals and man. 



In murine rodents, recovery of eggs from the Fallopian tube 

 involves first the removal of the tube from the abdominal cavity by 

 cutting through the utero-tubal junction on the one hand and the 

 mesosalpinx and ovarian capsule on the other with the aid of fine- 

 pointed scissors. It is advantageous to leave the ovary behind, 



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