Accurate photodensitometric measurement of the lecithin: sphingomyelin ration after elimination of the acidic phospholipids from extracts of amniotic fluid specimens.
Treatment of human amniotic fluid lipids dissolved in a chloroform/methanol (9:1, v/v) mixture by batchwise addition of diethylaminoethyl cellulose in a dry state proved to be an easy and rapid procedure for the removal of the acidic phospholipids which may interfere in the photodensitometric evaluation of the lecithin: spingomyelin ratio on a thin-layer chromatogram. This method was used for the measurement of the lecithin: sphingomyelin ratio in a series of normal and abnormal pregnancies. Ratios higher than expected from gestational age were observed in stressed pregnancies. A significant elevation of the ratio was also observed under treatment by dexamethasone.
D000653:Amniotic Fluid / Q000032:analysis*; D002855:Chromatography, Thin Layer; D003720:Densitometry / Q000379:methods; D005260:Female; D005865:Gestational Age; D006801:Humans; D008722:Methods; D010713:Phosphatidylcholines / Q000032:analysis*; D010743:Phospholipids / Q000302:isolation & purification*; D011247:Pregnancy; D013109:Sphingomyelins / Q000032:analysis*
D010713:Phosphatidylcholines; D010743:Phospholipids; D013109:Sphingomyelins