DNA extraction from sperm

May 6, 2005 10:52 AM

Does anyone have a good, detailed protocol for nuclear DNA extraction from a human (or other mammalian) sperm sample?

Our lab will be receiving a sperm sample and need to get DNA to use in PCR (and maybe quantitative PCR). Our problem is, we've never received semen before. I've worked with blood and tumor samples, but I'm concerned that there is enough difference between blood and semen that I can't use my normal protocol.
Also, I don't really know what to suggest to the lab sending the sample. Should we freeze the sample to avoid DNA degradation?

posted by nprigoda to science & nature (5 answers total)

This pdf seems to answer the question on extraction, at least with omission of some work - easily modified I sense.

Sperm freezing, also known as cryopreservation, has been practiced for many decades. Cryopreserved sperm is frozen in liquid nitrogen at a temperature of -196 °C.

source
(but that's obviously to obtain viable sperm for reproduction -- how much time between transfer? Ring a forensic lab? I'd think 'on ice' would do if it's intra-city and going to be processed upon arrival. But I don't know for sure.
posted by peacay at 11:21 AM on May 6, 2005

I think freezing a sample of cells (especially if you're gonna lyse them later) would always be the smart thing to do.

As far as a DNA extraction protocol, the literature for a kit I've used a bunch (here) seems to say that doing semen is no different from saliva or any other non-blood mammalian cell suspension. Proteinase K & detergent, RNAse, extract (the kit comes with some kind of salt but I like phenol & chloroform better), and alcohol precipitate.
posted by rxrfrx at 12:46 PM on May 6, 2005

I second rxrfrx's suggestion. A standard Proteinase K digestion following by phenol:chloroform extraction and ethanol precipitation should be fine. We have a good protocol that we use for mouse tails, skin samples and yolk sacs. Email me and I'll send it to you.
posted by greatgefilte at 12:51 PM on May 6, 2005

Any commercial genomic DNA column should work fine. I wouldn't worry too much about it. Qiagen has this protocol for sperm cells on their site.
posted by shoos at 1:31 PM on May 6, 2005

And DO freeze the samples. Obviously it's not sterile, and who knows what will grow in it at room temperature.
posted by shoos at 1:32 PM on May 6, 2005