title: Fetal lung maturity tests on the 10,000 X g pellet.
abstract: Centrifugation has a profound effect on tests of fetal lung maturity performed on amniotic fluid. We have investigated the effect of a 700 X g centrifugal force for 10 min and a 10,000 X g force for 20 min on a battery of tests. While 91% of the OD650 was removed by the 10,000 X g centrifugal force, the supernatant fraction retained 34% and 38% of the L/S ratio and enzymatic lecithin respectively, when compared to the sample before centrifugation. Phosphatidylglycerol, when present in an amniotic fluid, was always absent from the 10,000 X g supernatant but present in the pellet formed by this centrifugal force. The pellet after 10,000 X g was unsuitable for OD650 and L/S ratio determinations but contained 63% of the enzymatic lecithin. When the pellet tests were subjected to a clinical trial, respiratory immaturity did not occur when phosphatidylglycerol was present or when the 10,000 X g pellet may be a useful means of detecting amniotic fluid surfactant and thus determining fetal lung maturity.
authors: Department of Chemical Pathology, University of the Witwatersrand Medical School, Johannesburg, South Africa.
authors: J C
authors: JC
authors: McCulloch
authors: D
authors: D
authors: Mendelsohn
mesh_terms: D000653:Amniotic Fluid / Q000378:metabolism; D005260:Female; D005325:Fetal Organ Maturity; D005333:Fetus / Q000378:metabolism*; D006801:Humans; D008168:Lung / Q000196:embryology* / Q000378:metabolism / Q000648:ultrastructure; D010713:Phosphatidylcholines / Q000378:metabolism; D010715:Phosphatidylglycerols / Q000378:metabolism; D011247:Pregnancy; D011663:Pulmonary Surfactants / Q000378:metabolism; D013109:Sphingomyelins / Q000378:metabolism
chemical_list: D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D011663:Pulmonary Surfactants; D013109:Sphingomyelins