These specifications are designed to enable laboratory scientists, in vitro diagnostic (IVD) manufacturers, proficiency testing providers, and suppliers of clinical laboratory reference materialsa to prepare frozen human serum pools which demonstrate minimal matrix effects, are commutable across different cholesterol measurement procedures, and, as such, are suitable for assessing the trueness of these procedures. These serum pools, when assigned target values by the definitive method and/or reference method of the National Reference System for Cholesterol (NRS/CHOL), may be used to properly calibrate and/or assess trueness of field methods for serum cholesterol measurement, and provide an alternative method to split-sample comparisons with human specimens for establishing traceability of calibration of field methods to the NRS/CHOL. This document provides guidance for collecting and processing raw materials to manufacture frozen serum pools and for performing quality assurance of the final product. As part of the guideline development, two frozen human serum pools using a large number of selected individual donor units of "off-the-clot" serum were prepared and characterized. The performance of the pools was assessed in terms of the degree of commutability (observed response versus predicted response) relative to the individual sera which comprised the pools.