5.2.1. Sealing semen-filled capillary tubes

  1. Collect semen into glass capillary tubes of the syringe.
  2. Remove glass tip and detach the filled capillary tube.
  3. Force petrolatum into one end of the tube (~7 mm).
    a. Insert the capillary tube into the petroleum jelly perpendicularly several times until a sufficient plug is formed.
    b. The petroleum can be touching the semen or a small airspace can be collected between the semen and petrolatum seal.
  4. Reconnect the sealed end of the tube to the syringe and push the column of semen forward to allow space to seal the other end.
  5. Detach and place a petrolatum seal in the other end of the filled capillary tube.
  6. An alternative method, a glass bead connected with a small piece of silicone tubing, can also be used to seal the capillary tube. The glass bead is made by heating a small piece of capillary tube to seal both ends.
  7. Store in the dark at a temperature of 20ºC. Avoid sunlight and temperature fluctuations.