Jack Geller, the owner of Geller Labs, performed asbestos testing at a house we’re in the process of buying in Alexandria. All of the basics were covered: there on time, took samples carefully and from inconspicuous areas, polite, tests came back reasonably quickly, etc. I imagine that any company that wants to stay in business would meet those standards. Where Geller Labs went from perfectly competent to AMAZING is in the patience Mr. Geller displayed with answering questions. My dad had come along with me for the test, and my dad had a ton of questions informed by his own experience as a builder and with indoor air quality. Mr. Geller spoke at length, answered every question, opened up an air vent to check inside the duct work, and basically covered everything twice. Professional, patient, competent, and a genuinely nice individual. Would totally recommend Geller Labs if you’ve got shady stuff happening in your house and you want it professionally investigated.