Semen Dilution Calculations Made Easy
Volumes
- µl = micro liter
- ml = milli liter
- 1000 µl = 1 ml
- 1000 ml = 1 liter
Sperm Concentration
- Usually expressed as number of sperm X 10^6 / ml.
- For example – 250 X 10^6 / ml
Frozen Semen Calculations
We will assume you are diluting the centrifuged sperm to 250 X 10^6 sperm /ml as suggested and want 1 ml of extended semen.
- 250 / sperm concentration = volume in ml of semen to be added to tube
- 1 – volume of semen = ml of extender to add
- example, concentration of centrifuged sperm = 2000 X 10^6/ml
- 250 / 2000 = 0.125 ml semen, and 1 – 0.125 = 0.875 ml extender
- take 0.125 ml of centrifuged semen and add 0.875 ml of extender to give 1 ml of semen at 250 X 10^6 / ml.
- Simply repeat removing the calculated amount from the centrifuged sperm pellet, counting how many times you do this. Multiply the volume of extender times this amount and add to the semen.
- You are able to remove and pool 8 aliquots of 0.125 ml semen from the centrifuged semen.
- Add 8 X 0.875 = 7 ml of extender.