Normally carried out using 0.5cc straws. Note these have to be sealed with PVA sealing powder or ball bearings (from MTG).

Method as per MediCult* using their sperm freezing medium.

1. After liquefaction, measure the total volume of the ejaculate and carry out semen analysis as required.
2. Ensuring both the semen sample and the Sperm freezing Medium are at room temperature, dilute the semen 1:1 (v/v) with the SFM. The medium should be added dropwise to the semen and the solution carefully mixed after each addition.
3. The resultant mixture should be left at room temperature for a minimum of ten minutes.
4. Fill straws with the diluted semen and seal according to the manufacturer’s Recommendations.
5. At this point MediCult offer a vapour freezing method. This is still used in many laboratories.
6. However laboratories wanting a very repeatable method use a controlled rate Freezer and the recommended method is as below.

Start temperature 20°C……Filled straws are placed in the DB1 and the door closed.

Rate 0.5°C/minute to 4.0°C.

Freefall to -60°C………………Quickly remove straws and plunge into liquid nitrogen

END

Allow DB1 to warm up and then run dry or sterilise programme.

*www.medi-cult.com