Le raccordement métrologique des thermocycleurs au Système International (SI) dans le cadre de l’accréditation ISO 15189

A+ METROLOGIE, 191 rue de Vaugirard, 75015 Paris, France

^a Corresponding author: le.touze@aplus-metrologie.fr

Abstract

Biotechnologies are in full boom among them the molecular biology. Polymerase Chain Reaction (PCR) is the main technology that permits such development. This recent analytical methods allows from a small piece of DNA to obtain a large number of copies (millions) of this very same fragment. PCR is performed with a device named a thermal cycler or a thermocycler. This high-tech equipment realizes 30 to 40 very short temperature run so after 30 minutes DNA is duplicated in a necessary and sufficient quantity. The user distributes with a micropipette his sample in one of the well of the block reaction and push a button: looks like easy! That’s how such device is democratized as a routine diagnostic tool in medical laboratories. In order to confirm their competence, medical laboratories must be accredited by the ISO 15189 standard. Laboratory equipment such thermocycler, regarding the critical to the diagnostic provided, must be calibrated by an accredited laboratory (traceability). Without an ISO standard dedicated to perform thermocycler metrology, an internal protocol was created. This protocol is accredited Cofrac and rely to a physical method. This method allows to highlight the fact that thermal profile of thermocycler is unique! In order to compare devices together, to develop a strategy for test routines, to follow the drift of devices, the only solution is a unique and identical calibration program. This methodology should be standardized and give birth to a dedicated ISO. This is one of the next steps. Ensure the traceability of the real time PCR is the new challenge for the accredited metrological companies, by introducing optical metrology inside medical laboratories.