Final Answer:
For coagulation testing, additives such as sodium citrate are used. Ethylenediaminetetraacetic acid (EDTA) is employed for WBC testing, while pregnancy tests typically utilize urine samples without specific additives. For random glucose testing, sodium fluoride and potassium oxalate are commonly used additives.
Step-by-step explanation:
In coagulation testing, sodium citrate is crucial as it acts as an anticoagulant by binding calcium ions, preventing blood clot formation. The standard ratio is 9 parts blood to 1 part sodium citrate to ensure proper anticoagulation, maintaining the sample's integrity for accurate coagulation assessments.
For WBC testing, EDTA is the preferred anticoagulant, with a standard ratio of 1.8 mg of EDTA per milliliter of blood. EDTA works by chelating calcium ions, preventing clotting and preserving the morphology of white blood cells for an accurate count.
Pregnancy tests, on the other hand, usually do not require additives. They rely on detecting human chorionic gonadotropin (hCG) in urine, a hormone produced during pregnancy. The absence of additives ensures that the urine sample remains in its natural state for accurate hCG measurement.
In random glucose testing, a combination of sodium fluoride and potassium oxalate is used. Sodium fluoride inhibits glycolysis, preserving glucose levels, while potassium oxalate prevents clotting. The recommended ratio is 2 parts sodium fluoride to 1 part potassium oxalate, ensuring accurate and stable glucose measurements.