PA Bulletin, Doc. This approval is based on demonstrated proficiency in tests conducted by the Bureau of Laboratories of the Department of Health. Laboratories approved to perform screening tests only are designated on the approval list by an ''S'' after the laboratory's name. Laboratories approved to perform confirmatory testing only are designated by a ''C'' following the laboratory's name. Screening analyses provide a presumptive indication that a controlled substance is present.
Confirmatory testing is used to substantiate screening results.
Persons seeking forensic urine drug analysis services from any of the listed laboratories should determine that the laboratory employs techniques and procedures acceptable for the purpose. They should also determine that the director of the facility is agreeable to performing analyses for that purpose. Persons seeking the analyses are responsible for specifying the extent to which the presence of a controlled substance is to be verified. That specification should be predicated upon the purpose for which the analysis is being sought. The list of approved laboratories will be revised semiannually and published in the Pennsylvania Bulletin .