Reference values for a particular population is not readily available and the values used may be based on results of measurements in advanced countries, taken from the literature (of advanced countries) or from package inserts that accompany reagent kits. However, these parameters even in the healthy state are affected by several factors including age, ethnicity, gender and environment (including altitude). These differences may suggest the need for the development of locally derived reference values (for these parameters) to improve clinical care and also for monitoring participants in clinical trials. In establishing reference values, it is essential that the population is well defined and properly selected to be representative of that population, as the lower and upper limits of measurements are known to be more affected by the choice of the sample population, standardization of the sample collection and handling and analysis and also the statistical analysis. Prior to initiating any trial, it is imperative to establish the normal range of values for the laboratory indices that will be used to screen potential volunteers to determine if they meet the inclusion / exclusion criteria as well as assess safety in those volunteers who receive the test product.