A comprehensive classification of kinetic methods of analysis used in clinical chemistry

This paper presents a comprehensive classification of kinetic methods of analysis used in clinical chemistry. Objectives of the presentation are to place kinetic methods into perspective with other analytical appraoches, to identify concisely what is and is not a kinetic method, to group different kinetic methods into categories that identify important differences in operational and performance characteristics, and to suggest terminology that can identify the different approaches without ambiguity. In addition to these major objectives, the paper includes a brief historical development of the kinetic approach that covers the period from 1881 to the present, and discusses some current terminology that is believed to be ambiguous and misleading. I suggest that the detection step in analytical methods can be divided into two general categories, called equilibrium and kinetic methods. The kinetic methods are then subdivided into two general categories called fixed sensor-signal and variable sensor-signal methods. Each of these groups is then subdivided into one-point, two-point, and multi-point methods, which are then further subdivided according to what types of blanks are used, what variables are measured, and how the measured data are used to compute enzyme activity or analyte concentration. The paper identifies some commercial instruments that represent different approaches and briefly discusses relative merits of different approaches.