In my opinion, it is necessary to remove the gel droplets and also not to summarize their volume to the semen volume. These droplets are not often present, if the sexual abstinence is adequate.

Best regards

Pavel Travnik

Gel droplets in the semen cause lots of problems, It is not only that they add to the volume and must therefore be considered for the sperm concentration, but are also difficult to remove. Since they can block a density gradient or glass wool column, I would recommend having large parts of them sedimented first, then take the supernatant with the sperm and process. Depending on the situation, I would also do the sperm separation on more than one gradient or glass wool column to increase the separating surface.

Finally, one must be careful as these gel droplets can expand when they come into contact with the sperm processing medium. Then things get even worse as the gradient of the column gets even clogged more. Here, I am talking from own experience. I once had such a case.

Best regards

Ralf Henkel

After semen liquefaction, I put the semen sample in 15 ml conical centrifuge tube until all gel droplets are down. Then take the supernatant carefully and process by gradient density.

Best regards

Jimmy Portella

I work on bull and bison semen. I have no experience of human semen. You can try Sephadex ion-exchange column (paper attached), it is very effective in cleaning bull semen. It might work for gel droplets also depending upon their size.

With regards,

Anzar

For the semen analyses I conducted in 2014, 37% had at least 0.1 mL of gel droplet volume with a medial of 0.2 mL (0.1 - 1.6) with the gel making up a median of 9% of the semen volume.  We request 2-5 days abstinence, which is generally followed.  The amount of gel is pretty consistent for a given patient. 

The gel droplet dissolve in about 10-30 min at 37°C, but this increases processing time and exposes the sperm to the toxic effect of the seminal plasma for an extended time.  One reason I see so much gel may be that I insist on looking at the semen within 30 min of collection.

As Jimmy Portella wrote, the droplets are easily removed by centrifuging the sample (one minute at 200Xg), which does not sediment other seminal constituents.  I read the gel volume from the centrifuge tube and decant the supernatant back into the specimen cup.  None of the semen analysis reviews I have read (including the WHO manual) mention the gel (I would really appreciate any references any of you have seen about this). I was just wondering whether others did this routinely?

Gel droplets present in semen samples generally dissolved within 30-45 minutes after collection. For the semen analysis you have to keep the sample at least 45 minutes  at 37 C for complete liquefaction of the sample. If the gels appear even after that you can dissolve them gently passing through a pipette several times without forming air bubbles. If you find them even after that procedure you can remove them manually allowing them to settle. But this may affects slightly to the volume and concentration and you can mention this condition in your semen analysis report.

For the sperm preparation you wait for at least 30 minutes and if they present even after that, gently liquefy using a pipette without making air bubbles. But if there is a good sperm count in that specific sample you dont worry to dissolve them and remove them allowing to settle down in to a bottom of  a conical tube. But if the sperm count of the sample is very low you can try to dissolve by pipetting or enzyme digestion using alpha amylase or chymotrypsin and perform the density gradient separation. 

You may want to talk to Peter Sutovsky in Animal Science dept in your university. He might be a useful resource you have on campus in this field.

I process semen for electron microscopic examination and do not want to have these gel droplets that diminish the density of sperm cells in the pellet, so I always remove them by a brief centrifugation (less than 30 seconds) in a table top centrifuge. They pellet quite rapidly while spermatozoa do not. Then I decant the semen (never use aspiration because gels may be re-suspended ! ) and proceed to centrifuge it to obtain the sperm pellet. I works very well.