Reference materials used in the program are prepared from pooled human serum according to the Clinical and Laboratory Standards Institute (CLSI) guideline C37-A (Preparation and Validation of Commutable Frozen Human Serum Pools as Secondary Reference Materials for Cholesterol Measurement Procedures; Approved Guideline) (5, 6). Portions of the sterile, filtered serum are dispensed into glass vials, which are sealed then frozen at -70°C.
LSP reference materials are stored and maintained frozen at or below -70°C. (Storing and maintaining HDL-C materials at or below -70°C is critical.) All such materials are shipped to participating laboratories by air mail special delivery in special insulated containers with sufficient dry ice to last at least 48 hours in the case of domestic delivery. Additional dry ice is added, as permitted, for delivery to international participants. Upon arrival, the frozen reference material must immediately be transferred to a freezer for storage at -70°C.