Clinical Chemistry, Vol 27, 1424-1426, Copyright © 1981 by American Association for Clinical Chemistry

Sedimentation of lung-derived phospholipid during low-speed centrifugation of amniotic fluid

CG Duck-Chong, LM Brown and WJ Hensley

In most methods proposed for the assessment of fetal lung maturity, amniotic fluid is subjected to a preliminary low-speed centrifugation in an attempt to separate whole cells and cell debris from lung-derived surfactant phospholipid (lamellar body phospholipid). However, because lamellar body phospholipid is present in amniotic fluid in a membranous or particulate form, it is also partly sedimented by this procedure. The sedimentation of total phospholipid and lamellar body phospholipid by low-speed centrifugation has been quantitated for 49 samples of amniotic fluid from pregnancies of 30--41 weeks gestation. Isopycnic density-gradient centrifugation in a small air-driven ultracentrifuge was used to isolate lamellar body fractions from whole and centrifuged amniotic fluid. Centrifugation for 5 min at 1000 x g removed 0--70% of total phospholipid or lamellar body phospholipid, the mean values being 34 or 29%, respectively. There was an appreciable increase in lamellar body phospholipid relative to total phospholipid as a result of centrifugation in only 51% of the samples. In general, the effects of centrifugation were not related to gestational age of the fetus or the state of maturity of its lungs.

The following articles in journals at HighWire Press have cited this article:

				D. G. Grenache, C. A. Parvin, and A. M. Gronowski Preanalytical Factors That Influence the Abbott TDx Fetal Lung Maturity II Assay Clin. Chem., June 1, 2003; 49(6): 935 - 939. [Abstract] [Full Text] [PDF]