Measurements in clinical chemistry are performed at several levels of healthcare facilities ranging from large hospitals to commercial laboratories. Physicians increasingly rely on measurement results for objective diagnosis and monitoring of treatment effects. Healthcare decisions for individual patients are influenced by the results of all measurements, irrespective of which measurement methods and systems they originate from. Unlike most of the industrial QC, the medical diagnostic laboratory determinations are totally different because of the huge biological differences among human beings. Statistical Quality Control (SQC) is used for this purpose. SQC can be done only for the equipment and the analytical methods and rarely for each laboratory result. SQC of automated analyzers does not use patients’ results but the results of some special samples, termed QC material.

At individual laboratory level; control materials (or simply “controls”) are used for error detection in SQC. Control samples are pools of biological fluids (serum, whole blood, urine or other materials). They contain analytes which are determined by the laboratory, ideally in concentrations/activities close to the decision limits where medical action is required. In internal and external SQC, it is common practice that laboratories use two or three different control samples which contain different quantities of analytes or their activities.

In a big picture, the minimal criteria for the performance of individual measurement methods and systems are frequently decided by national or international organizations and, consequently, their performance is monitored accordingly. Q-line® Biotech presents multicontrols of two levels from two different brands: 'ELITROL’ and ‘LABTROL’. The former is a lyophilysate of human serum, a product of ELITech Group, France and the latter is a bovine serum lyophilysate, a product of CHEMELEX S.A, Spain.  Both the controls exhibit an excellent commutability with patients’ serum when used with Q-line reagents.