Pictorial representation of the study methodology using 2 tests: RP-HPLC and ELISA. HPLC (high-performance or high-pressure LC) is an analytic chemistry technique used to separate, identify, and quantify individual components in a mixture. A solution containing the mixture is passed through a column with adsorbent material. The different components of the mixture react with the adsorbent material leading to separation of the components as they flow out of the column. RP-HPLC uses hydrocarbon chains to generate a stronger or higher affinity for polar components, essentially the reverse of normal-phase chromatography. ELISA is a commonly used analytical biochemistry technique. It uses an enzyme immunoassay to detect the presence of a protein by directing antibodies to the protein to be measured. HPLC and ELISA have been used for biologic and pharmaceutical manufacturing, laboratory testing (of urine and blood) and in research for separating and identifying the individual components of a complex sample.