In the U.S., there are a number of different private laboratories. I choose to go to Germany, myself, and the ELISpot test I use from a few different labs in Germany is available in a certain lab in the United States as well.
Diagnosis is very difficult. The standard in the U.S. is looking at a certain number of bands, whereas other countries have said that this makes no sense: either you have five bands or you have nothing. What about somebody who's very suggestive and has four bands? We need to report that out, because if the picture is really suggestive, how can you set such a hard and fast limit, which the infectious disease people set 20 years ago as their criteria?