Studies on the Antigenic Stability of Hepatic Triglyceride Lipase in Human Postheparin Plasma during Long-Term Storage

The present study describes how to process human postheparin plasma (PHP) containing hepatic triglyceride lipase (HTGL) that is utilized as a standard material of HTGL for the quantification of HTGL mass in human plasma. The optimal storage conditions for PHP were established by monitoring the stability of HTGL molecules in PHP as an antigen, which was stored in the liquid, frozen, or lyophilized state, using purified human PHP-HTGL as the standard material and a commercial HTGL ELISA MARUPI kit, which is a direct sandwich enzyme-linked immunosorbent assay (ELISA). The HTGL ELISA MARUPI kit, for which the validity was confirmed by precision and dilution tests, showed that the immunoreactive mass of HTGL in lyophilized PHP remained stable for at least 12 months at a storage temperature of 4°C or lower. These results indicate that lyophilized PHP stored at a temperature of less than 4°C can be utilized as the standard material for the quantification of HTGL in human plasma using the HTGL ELISA MARUPI kit.