Automation in the field of diagnostics has lead to a revolution in the hardware and software of clinical chemistry analyzers, also called auto analyzers. In the field of diagnostics, a clinician or pathologist needs quick, reportable and accurate results, which are cost effective too! In this modern era, several models are available which serve this purpose. Fully automated clinical chemistry analyzers are made up of three major components: (1) robotic arms, called probes, controlled by pressure valves, (2) a photometer that measures the light from built-in cuvettes which are held at a constant temperature, and (3) a microprocessor or software package which calculates the values from the signal and then displays the data in a user-defined format.
Many companies supply dedicated systems which require the use of specific kits made by the instrument manufacturer. These are closed systems. Many other companies supply instruments which allow the user the freedom to use kits from any supplier. These are open systems and require careful programming of parameters.
In our organization, during the time of instrument selection, we screened all available instruments. Through careful study of the specifications provided by the vendors, we selected Olympus AU400 on the basis of its technical superiority to others. In the model name AU400, au represents gold (remember aurum!) and the number indicates its throughput. This is a fully automated and open system. The instrument has two permanent probes: a sample probe (2 – 50 µl) and a reagent probe (20 – 300 µl). The probes have good accuracy and precision (CV<3%, proven using the zig module from the vendor). The reagent chamber is refrigerated and accommodates 72 reagent bottles. If required, 46 parameters can be analyzed at a time. The STAT table is also refrigerated and the system offers true STAT means emergency analysis. This halts all other analyses and prioritizes the STAT samples immediately. The system can accept 80 samples at a time from a rack and allows continuous loading.
The software used in the system is Windows 2000®, built on an NT® platform. The hard disk has storage capacity for data from 10,000 patients; storage capacity becomes infinite if linked to a server. The software also has the ability to perform online data transfer and remote maintenance. We are primarily concerned with quality results and hence, we have dedicated positions for calibrators, controls, and blanks in the STAT table, which has made our calibration and quality control (QC) easy. The QC menu of the software offers L-J graphs, west guard rules, etc. for user review. The data can also be stored and printed.
At our organization, we are using this system for the clinical analysis of biological samples like serum, plasma, and urine for various research projects. We are using this system for numerous animal species, including rats and mice. Depending on the requirement of the study, the number of samples varies from 50 to 165. Parameters include routine as well as special parameters. Routine parameters include liver function tests, renal function tests, glucose tolerance tests; special parameters are free fatty acids, HbA1c, ketone bodies and much more. We have used the system with Olympus kits. We have participated in an external quality assurance program, which has increased our confidence in terms of the system’s quality. The Olympus AU400 has scored good to excellent in various parameters. The system is performing more than satisfactorily.
Himanshu Pathak
Scientist
Torrent Research Center
PCSE (Pre Clinical Safety Evaluation)