title: Laboratory variables in determining lecithin/sphingomyelin ratios.
abstract: The results obtained for amniotic fluid lecithin/sphingomyelin ratios are method-dependent. Some of the method variables which affect the assay are the presence of blood or meconium, the conditions of centrifugation, the spray reagent used for visualization following thin layer chromatography, and variations in the techniques used for quantitation of the spots. Control of these variables is necessary if the results are to be reliable and useful.
mesh_terms: D000653:Amniotic Fluid / Q000032:analysis*; D001769:Blood; D011232:Chemical Precipitation; D002855:Chromatography, Thin Layer; D003720:Densitometry; D005260:Female; D006801:Humans; D007202:Indicators and Reagents; D007231:Infant, Newborn; D008470:Meconium; D010713:Phosphatidylcholines / Q000032:analysis*; D011247:Pregnancy; D013048:Specimen Handling; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D007202:Indicators and Reagents; D010713:Phosphatidylcholines; D013109:Sphingomyelins