Enzymatic clarification of hyperlipidemic specimens-Its rationale and limits

Enzymatic clearing of severely hypertriglyceridemic specimens is a relatively new technology for providing optical clarity in spectrophotometric procedures, thereby avoiding the interference of severe light-scattering. Interestingly, such specimens can show interference in the determination of any of the major lipids of serum. In addition, the common current procedures for partial or complete clarification of opaque specimens, namely ultracentrifugation and organic extraction, respectively, cannot be used when cholesterol, phospholipids, and/or triglycerides are desired constituents because they would be removed quantitatively in the case of organic extraction or variably in the case of ultracentrifugation. The present report was developed to show the characteristics of enzymatic clearing which differs from other means of clarification in that the sample is not pretreated. Instead, the reagents are altered so that the conversion to spectrophotometric clarity occurs while the intended equilibrium reaction for measurement is in progress. The need for a scavenger to become the host for liberated nonesterified fatty acids eliminates the potential to provide any new turbidity or reaction with serum or reagent components. The hallmark of this host-guest complex is that the latter is soluble and transparent. Included in the report is a special study using the choline-phospholipids of serum as a model for providing some insight into how on-line clarification owing to an altered reagent matrix is developed.