We talk about the issue of sensitivity. If I'm going to use a DNA marker, how sensitive is my DNA marker to the presence of low amounts of DNA of that species? We have thousands of genes in our DNA, and you have to select the right gene. We know from previous work which genes we should be looking at. Then within those genes you need what are called primer pairs. Primer pairs allow you to bind onto the DNA. Each primer pair is going to have different sensitivities. What you have to do in the lab for each species, you would have to test different genes and different primer pairs for each gene to determine which of them had the most sensitivity. They could vary up to seven orders of magnitude. We're talking a vast difference in the potential use. You then pick the ones that have the highest sensitivities. That means they are best able to find DNA of a species when it's present at minute quantities in the environment. This is where the significant start-up cost is.
Of course, you have some machinery that you have to get to do the work. For each of the species that you're concerned about, you have to do some significant lab work in order to determine which gene you are going to go forward with in the future. It's going to be different for every species that you choose. Once it's been done you would publish this stuff in public databases, and everyone else in the world would be able to use that same gene and that same primer pair into the future.