What is the minimum sample size adult reference population required for Laboratory Developed Tests (LDTs)?

In general, more samples/measurements provide better estimates with less uncertainty. However, the number of samples is often limited by sample availability and budget concerns. For this reason, the Clinical and Laboratory Standards Institute (CLSI) recommends 20 measurements to verify a manufacturer's claim and suggests a minimum of 60 data points (e.g., 12 measurements from each of five samples) for a manufacturer to establish a Limit of Detection (LOD) claim. For more information, consider reading this paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2901657/.