CLSI LA04-A5 addresses the issues associated with specimen collection, the filter paper collection device, and the transfer of blood onto filter paper. The purpose of these considerations is to produce a functional standard that will result in uniform techniques for collecting the best possible specimen for use in newborn screening programs. Issues addressed in the standard include: procedures for applying blood collected by heelstick directly onto the preprinted circles of filter paper; recommendations on the source of blood; other techniques for collection of blood spot specimens; specifications for the filter paper, handling, and the mailing package; specifications for the specimen collection device; the handling of blood spots collected on filter paper for DNA/RNA analysis.