Abstract: A simple rapid STAT test and test kit are provided for the reliable determination of prenatal lung maturity as well as other surfactant lipid dependent determinations. The method involves a shake test employing a plurality of vials having graduated volumes of ethanol, including a dye, normally in combination with a positive control. A predetermined amount of the sample is introduced into each of the vials, the vials shaken in a reproducible manner, and the highest ethanol volume fraction which provides for a stable foam determined. Based on statistical evaluations, an ethanol volume fraction above 0.45 will generally be regarded as positive, meaning healthy lung maturity, while a value below about 0.45 will generally indicate that further investigation is warranted.