title: Letter: Considerations in determining lecithin-sphingomyelin ratio in amniotic fluid.
mesh_terms: D000096:Acetone; D000653:Amniotic Fluid / Q000032:analysis*; D002498:Centrifugation; D011232:Chemical Precipitation; D002725:Chloroform; D002855:Chromatography, Thin Layer; D005260:Female; D006801:Humans; D000432:Methanol; D008722:Methods; D010713:Phosphatidylcholines / Q000032:analysis*; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins; D000096:Acetone; D002725:Chloroform; D000432:Methanol