I would say that the correct coding would be lab services, especially since this is self-sampling and not collected by a hospital or clinic. The fees are only for the lab service of testing the samples.
730251 Patient Care: Fees for laboratory or medical services, including patient care, provided by physicians, counselors, psychologists, dentists, and other health professionals, including hospitals and clinics.
720403 Lab Services: Scientific services for research laboratory, classroom, medical, and dental use, such as microscopy, synthesis, production of supplies for dental use, blood drawing, lab send-outs, etc.