Cornell university extender (CUE)

CORNELL UNIVERSITY EXTENDER (CUE)

Foote et al. (1958) at Cornell University developed the following dilutor for the preservation of semen at room temperature (20-24oC).

S.No. Components Quantity
1 Sodium bicarbonate 0.210 per cent
2 Sodium citrate 1.450 per cent
3 Potassium chloride 0.040 per cent
4 Glucose 0.300 per cent
5 Glycine 0.909 per cent
  • To this citric acid 0.12% and 2 mg of catalase per 100 ml of dilutor was added. Antibiotics are also added to control the bacteria.
  • Reaction of citric acid and bicarbonate releases CO2 which helps in prolonging sperm life.
  • Small quantity of CO2 is also produced by spermatozoa from the breakdown of glycine via glyoxylate mechanism, and glyoxylate itself is an effective inhibitor of respiration.
  • Thus, in medium to which glycine and citric acid are added in addition to bicarbonate, there is no need to infuse extra CO2.
  • The gas generated in the medium is sufficient to curtail respiration of spermatozoa and immobilize them temporarily.
  • Addition of catalase at room temperature preservation was necessary to act on hydrogen peroxide produced by spermatozoa from amino acids.
  • Semen can be preserved for 3-6 days with 70-80% fertility on non return basis.

CU extender can be used to preserve semen for 3-6 days at room temperature.

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Last modified: Monday, 4 June 2012, 11:29 AM