EDTA tubes are more frequently associated with carryover contamination than any other types of additives, while heparin is associated with the least amount of interference. Coagulation tubes, which contain sodium citrate, are the first to be filled because all other additives interfere with coagulation tests. Partial thromboplastin time (PTT) tests are affected by tissue thromboplastin contamination.

If the phlebotomist notes than an aliquot of serum contains a fibrin clot, the most likely reason is that centrifugation was carried out before clotting was complete. Fibrin clots are likely to form if hemolysis occurs, usually from mishandling a specimen or leaving the tourniquet on for too long. Fibrin clots may appear as globules (opaque or gelatinous) or strands in serum or plasma. In most cases, an aliquot with a fibrin clot needs to be discarded.

The Clinical and Laboratory Standards Institute (CLSI) provides standards for a wide range of performance and testing and covers all types of laboratory functions, including microbiology'. The institute comprises representatives from the healthcare professions, industry, and government. These standards are used as a basis for quality control procedures. Standards include labeling, security/information technology, toxicology/drug testing, statistical quality control, and performance standards for various types of antimicrobial susceptibility testing.

Liver function tests are not part of dementia screening, which is done to try to differentiate Alzheimer's disease from dementia related to other disorders. Dementia screening includes general tests for disorders that may present with dementia as one of the symptoms. Tests include thyroid and kidney function tests as well as WBC (white blood cell count) and RBC (red blood cell count). Other tests include HIV antibody, vitamin B1 2, syphilis screening, ESR (erythrocyte sedimentation rate), alanine transaminase, aluminum, and toxicology' screening.

The antiseptic that is most commonly used for cleaning the venipuncture site is 70% isopropyl alcohol, which is more effective at destroying pathogens than 90% isopropyl alcohol is. Povidone- iodine may also be used, and is generally used for blood alcohol testing, but it must be removed from the skin after the venipuncture. Chlorhexidine gluconate may be used as an antiseptic as well; it is sometimes mixed with 67% isopropyl alcohol.