Synovial fluid Collection:
The technique of obtaining synovial fluid is called arthrocentesis. It is used to characterize type of arthritis and to differentiate inflammatory from non inflammatory effusions.
Sterile plain tubes are used for culture and for glucose and protein estimation; EDTA tube is used for a total leukocyte, differential, and erythrocyte count.
Amniotic fluid Collection:
The procedure is called amniocentesis and is done for prenatal diagnosis of congenital disorders, to assess fetal maturity, or to look for Rh isoimmunization or intrauterine infection.
Skin should be cleaned, and 10 mL of fluid is aspirated into a syringe. Glass containers are used to transport the fluid to the laboratory.
If the specimen is for determination of lecithin/sphingomyelin (L/S) ratio, the container is immediately placed in ice; if it is for spectrophotometric, the specimen should be transferred to a brown tube or bottle to prevent photodegradation of bilirubin.