I am trying to solve the problems with extracting DNA in the dried blood spot (DBS) with the one-step Quantabio Extacta DBS buffer for qPCR reactions.

https://www.quantabio.com/extracta-dbs

We use Hamilton Microlab Starplus, a robotic liquid handling system, to process DNA extraction.

https://www.hamiltoncompany.com/automated-liquid-handling/platforms/microlab-star

There is no PCR amplification if the buffer sits outside for too long (more than 2 hours). I don't know if this is common for Extracta DBS buffer, because we need the buffer to be there for 8 hours in order to process a huge amount of samples. The temperature and CO2 in the air can change the pH of the buffer, but there seems to be a very wide range of pH for the DNA extraction, so it is hard to find the reasons for the bad PCR results. An alternative way is to use a pump and tubing system to get the buffer from an isolated bottle. However, we have to be sure that there is no DNA in the tubing or bottle. Is there a good way to get rid of any DNA in the tubing system? Does autoclaving or gamma irridation work?