Frequently Asked Questions: Sil-Select Plus

FAQ1: Does Sil-Select Plus contain antibiotics ?
No it doesn’t.
If you want to add your own antibiotics we suggest adding 10mg of pharmaceutical grade gentamicin per liter of medium.

FAQ2: How long can I use Sil-Select Plus after opening the bottle?
Two factors limit the shelf life of a product after opening the bottle:

  • Gass exchange: influences the pH
  • Contamination with viable organisms

We have performed open bottle tests on our media for up to 7 days and found that the product parameters stayed within the specifications in this time period, taking into consideration that the bottle was opened under sterile conditions and stored at 2-8°C after opening.

FAQ3: Can we make our own gradients instead of using your upper and lower layer density gradients ?
Yes you can, for that you would need to order Sil-Select Stock instead of Sil-Select Plus.
Note however that Sil-Select Plus gradients have been optimized for maximum efficiency in the selection of spermatozoa.

FAQ4: What is the advantage of the inclusion of Human Serum Albumin in the formulation of SIP?
Inclusion of HSA reduces the unintended adhesion of heavily moving spermatozoa to glassware.

FAQ5: How to handle a bad semen sample with a volume larger than 2.5mL?
Use more than one tube, with a maximum of 100×106 cells, where the ideal volume ratio of upper layer/lower layer/semen isn’t altered (2.5mL each). The gradient/semen can be centrifuged for an additional 5-10 minutes (total of 23-28 min @ 400g). Sil-Select 80% might be used intead of Sil-Select Plus Lower Layer (more sperm cells will pass through the layers).

FAQ6: How long after liquefaction can gradient centrifugation be performed?
Gradient centrifugation should be performed as soon as possible.

FAQ7: How to resuspend the pellet after centrifugation?
A syringe or micropipet can be used. Vortexing should be avoided because this can harm the spermatozoa.

FAQ8: Which medium should be used for washing after performing density gradient selection?
FertiCult Flushing medium or Sil-Select Plus Sperm Washing/Insemination medium.