--and how familiar the doctors around the area are with the procedure.

It is not the actual biopsy itself that is difficult--even most first year residents can give people shots of local anesthetic and then carve off a 3mm wide/1 mm deep piece of hairy skin and put a band aid over it. It's the analysis that is not widely available, as it involves electron microscopy, special staining, and very specialized training to interpret the results. This is why places like Johns Hopkins, the place at which this was first developed, sends out kits to other doctors but then requests the samples go back to it for analysis.

Places that analyze the samples (besides Hopkins) are Cornell Weill/Columbia Presbyterian in New York, Massachusetts General in Boston, the Jack Miller Center in Chicago, and a few others.