I am trying to amplify DNA from faecal pellets of the water vole. I have tried several different extraction techniques and up until christmas was getting a faint band of product from the PCR's I was doing. However since christmas everything has stopped working! I've tried replacing all of my PCR reagents, extracting new samples, using both microsatellite primers and mitochondrial (the mitochondrial ones are the ones that worked before christmas. I'm fairly certian its the PCR thats going wrong not the extractions becasue the PCR on samples that were extracted before christmas (and gave a product before christmas) now dont show product after the PCR. I'm going to try chaing the quantities of BSA I'm using, increasing the number of cycles (although I'm already doing 35), increasing the time of the elongation step and adding DMSO and I cant seem to find much in the literature which is helpful.
Does anyone have any other suggestions of things I could try to get it working?