How do I Determine Sperm Motility Rate?

The motility of sperm, or how many sperm cells are moving and how fast, is important in reproductive health. Sperm that do not move cannot fertilize an egg. Although it is relatively easy to see sperm moving under a microscope, determining the motility rate in a way that can be used for medical purposes is more challenging. In fertility clinics, it is normally done using automated computerized image analysis equipment. The method is the same whether the source is a human or an animal.

Instructions

Preparing the Sample

• 1

  Ensure the correct temperature. Normally, sperm motility in the laboratory is measured at 64.4 to 75.2 degrees Fahrenheit, although measurements at up to 98.6 degrees Fahrenheit are possible.

• 2

  Place a small sample of semen (approximately 10 to 12 microliters), preferably fresh, on a microscope lamella, and cover it with another lamella. The lamella should be 20 by 20 or 24 by 24 millimeters in size. The lamella size makes it possible to compare different samples and hence make a standardized measurement of motility.

• 3

  Ensure that the sample thickness is approximately 25 to 30 micrometers. This is achieved by using standardized lamella.

• 4

  Leave the sample to stabilize for approximately 1 minute.

Measure Motility

• 5

  Count the sperm in the sample. This is normally done with the microscope set at 400 to 600 times magnification and in a left-up fork movement.

• 6

  Count the number of sperm who are moving in different ways. Sperm motility is measured in four ways: rapid progressive motility, slow progressive motility, unprogressive motility (they are going round in circles), and amotility (not moving at all). The first two measure how fast the sperm is moving towards the target.

• 7

  Count the number of sperm in each category. This is usually done by counting the number of sperm in each category in four to six microscopic fields.

• 8

  Calculate the motility rate. This is done by taking the number of immobile sperm and the number of total sperm. Then, the number of of immobile sperm is divided by the number of total sperm. The derived number is subtracted from the total sperm number, and then the result is multiplied by 100.