Ok, where do we start? I think the beginning would be best.

Five weeks ago everything was running smoothly, my PCRs were working, the lab training of the med students just finished, all buffers were filled up and my PhDs were working peacefully beside me in the lab. Everything was nice, things were good.

Fast forward to next week. The gels are empty. Only two of my eleven PCRs gave me a result. "Ok", I thought to myself, "Shit happens. Lets prepare everything fresh and start over again. It'll be fine." Only, things weren't well. My gels kept laughing at me with their blankness and my frustration grew. I changed every little bit I could think of: Exchange my own Polymerase for a fresh tube of commercialy available Polymerase, open fresh dNTP-alliquots, use new dNTPs, exchange the water - because that's what you do, right? - prepare new primer dilutions, run all the PCRs as touchdowns, use fresh buffer, use a different buffer, exchange the enhancer from the Polymerase kit with lab prepared 5M Betain, do a phenol chloroform clean up with the sample, use a diffenrent cycler from another lab, etc. You name it, I tried it. I'm done. I created an account soley to answer this riddle, that even my PI can't solve. I'm desperate to say the least.

Even a change of extraction method with a very simple PCR didn't result in satisfying results.

As I said, the PCRs and the extraction method are well established in our lab and just stopped working from one day to the next. (or from friday to monday if you wanna be precise)

Over to you, do you have any clue what is killing my patientce with genotyping?