FAQ1: Can sperm be used for ICSI after the hypo-osmotic swelling test?
No, the test is not validated for clinical use of spermatozoa.

FAQ2: Is there a method for QC testing of the HOS Test that can be performed by users in the laboratory?

A. Standard QC test

1. Let semen liquefy and keep the sample at 37°C.
2. Determine the percentage of spermatozoa with curled or swollen tail before the test.
3. Transfer 1 ml of HOS solution to an Eppendorf tube. Keep the closed Eppendorf tube at 37°C for 5 minutes.
4. Add 100 µl of liquefied, warmed semen to the 1 ml HOST solution and mix gently.
5. Keep at 37°C for at least 30 minutes (but no longer than 120 minutes).
6. Evaluate 200 spermatozoa by microscopy at 200x or 400x magnification (preferably with phase-contrast microscope) and observe the swelling of the tail.
7. Repeat the above steps wit the old lot number.
8. Compare the results of the old and new lot number.
9. Results shouldn’t differ more than 10% between old (reference) lot and new lot.

B. Ethanol test

1. Measure vitality of native semen sample as described above or in the instructions for use of the HOS Test.
2. Add ethanol to the sample so that the end concentration of ethanol is 21%, all spermatozoa will be dead after 5 minutes.
3. Measure vitality of the semen sample with ethanol.
4. There should be a clear difference between the native sample and the sample spiked with ethanol. The number of dead cells should be higher in the samples that were treated with ethanol.