Use of the sulfo-phospo-vanillin reaction in a routine method for determining total lipids in human cerebrospinal fluid.

Adult human cerebrospinal fluid (CSF) was assayed for total lipid levels by the sulfo-phospho-vanillin color reaction. Lipids in a 1-2 ml sample of CSF are extracted with a 2:1 chlofoform-methanol mixture and the solvent extract, after equilibration with 0.74 percent potassium chloride, is evaporated to dryness. The lipid in the residue is estimated by the sulfo-phospho-vanillin reaction. The extraction process is essentially quantitative for lipid mixtures normally found in CF. The technique has an average coefficient of variation of 1.5 percent and the recovery of added lipids is nearly quantitative. It can be used as a rapid routine method for estimating CSF total lipids and several samples can be processed simultaneously. Estimations of total lipid levels using the sulfo-phospho-vanillin reaction agree quite well with the results obtained by densitometric quantitation of charred lipids. A preliminary analysis of 22 samples of adult human CSF containing normal levels of total protein gave an average total lipid level of 0.78 (+/- 0.07 SEM) mg/dl. Total lipid levels in CSF did not significantly correlate with age. However lipid levels in CSF show a significant positive correlation with CSF total protein levels.