Interest of water quality in Clinical laboratory experience of the central laboratory of Mohammed VI University Hospital of Oujda

Abstract

Water is the most used reagent in clinical laboratories. It is used for all levels of chemical, biological and physical analysis. It is important to know the type of water used because many analyses can be affected by its quality. Several agencies have established preparation and purity criteria for water.The objective of our work is to highlight the interest of water quality in the laboratory by presenting the experience of the Central Laboratory of Mohammed VI University Hospital of Oujda.Classically, water was classified according to a 3-tier system (Type I, II and III) by the National Committee for Clinical Laboratory Standards (NCCLS) which has been replaced by a more specific system developed by the Clinical and Laboratory Standards Institute (CLSI) guidelines that recommend the use of pure water for optimal laboratory testing. Clinical Laboratory Reagent Water (CLRW) is defined as the minimum quality water appropriate for routine biochemical testing.Poor water quality can have a great influence on the preparation of culture media, the preparation of reagents and dyes, the reconstitution of lyophilized material, dilution techniques are procedures that can be affected by laboratory water and may greatly influence the results obtained.Different techniques are used for water treatment such as filtration, distillation, reverse osmosis, ultraviolet photo-oxidation, deionization and many others.The water used in our laboratory is ultrapure, it contains only H20, as well as a balanced number of H + and OH– ions. It has a resistivity of 18.2 MΩ.cm, a TOC < 10 ppb, and a bacterial count < 10 CFU/ml.In order to guarantee this best quality, we use a unique system integrating five water treatment technologies. This will constitute a solid basis to guarantee the reliability of the results of the examinations according to the NF EN ISO 15,189 standard, a laboratory accreditation procedure in which we are engaged.