An amniotic fluid sample is collected via amniocentesis and the sample is spun down in a centrifuge at 1000 rpm for 3–5 minutes. Thin layer chromatography (TLC) is performed on the supernatant, which separates out the components.<unk>  and<unk>  are relatively easy to identify on TLC and the predictive value of the test is good.
Lecithin–sphingomyelin ratio
Lamellar body count
Sucrose gap
Anton blood group antigen
Alkali denaturation test
Osmol gap
Euglobulin lysis time
Gluten immunochemistry