We have been attempting to increase the volume of our extracted DNA using a Whole Genome Amplification (WGA) kit. In contrast to the more common PCR which amplifies a specific region of the DNA, the WGA process amplifies all of the DNA in a sample. This is great if you have very small amounts of DNA, but the downside is that if there is any non-sample DNA present that will amplify along with your sample.
My science partner and I spend about 2 weeks trying to work with our WGA kit. In order to make sure we were really amplifying our sample DNA and not a contaminant that we inadvertently introduced we used water as a negative control along side our sample. If we did things correctly we should have seen amplified DNA in our sample and no DNA in the water control when we were done. However, time after time we had more DNA in our water control than we did in the actual sample. This was very frustrating. We tried everything we could think of to be more sterile, and kept getting the same result. Finally we contacted the company and they sent us a new kit to work with. The first time we used it we got good results! There was no DNA in our water control, and plenty of DNA in the sample. It is really good to know the process works, and now we might actually be able to send some DNA out for sequencing. I am beginning to believe all the people who have told me that in molecular biology you do something over and over and over and over again... and then, finally, it works.