Quality Control (QC) materials and procedures are key to meeting the needs of doctors and patients by verifying accuracy and precision of analytical methods. Vendors of these systems can be a valuable resource, designing customized QC materials and protocols to help lab managers ensure that analytical error stays within acceptable limits.
Developing suitable QC materials for today's laboratories is a demanding business. Although the ideal QC material must closely resemble the human sample, providing an equivalent matrix without unnecessary and potentially interfering preservatives, it must also be stable for long periods without special storage needs. It must be conveniently packaged and inexpensive. The material should be available with two or more different levels of analyte, to control the assay across the normal and abnormal range. It must contain known concentrations of the analyte, but it should not contain communicable disease agents. For convenience, a single set of QC materials should contain several analytes tested within the same lab. Finally, the vendor should provide a user support program, assisting customers with data analysis to track the performance of their assays.
With the growth of medical technology and the variety of current analytical methods, the days of a single lyophilized control, used throughout the chemistry laboratory, are long gone. Large medical laboratories are divided into separate analytical areas, for example, toxicology, immunology, and STAT labs, each of which provides a different subset of testing and needs specialized QC materials. Each of these materials would, in turn, be inappropriate for a smaller hospital or a POC laboratory.
Modern medical labs also require a variety of quality control materials because of the variety of samples they handle every day. A single assay, for example, may be performed routinely on s erum, plasma, urine, and cerebrospinal fluid. For this one assay, three QC materials may therefore be required.
Packaging can also be a determining factor in the ideal QC material. How many assays a lab performs, and how much volume is used per assay, will dictate the volume of QC material the lab uses, and what size vial the user prefers. The ideal material will also be available at a reasonable cost, on an as-needed or standing order basis, and be backed up by good customer service and appropriate data analysis programs from the vendor.
Fortunately, new QC materials are keeping pace with the demands of laboratory customers. For specialty labs within clinical chemistry, QC materials containing a variety of immune, autoimmune, endocrine, lipid, and drug analytes are available. Serum, urine, and CSF controls are available for relevant clinical chemistries. Other materials are designed for QC in coagulation, hematology, infectious disease, or serology labs. These materials often are available in several sizes and packed as sets representing normal and abnormal analyte concentrations. Unopened vial shelf life may be years; open vial shelf life is often a week or more. For the lab requiring a unique analyte, an unusual combination of analytes, or a special matrix, vendors like Quantimetrix can design custom QC materials and maufacture them to order.
Vendors of these new materials also supply data management and customer support to provide laboratory customers with a wealth of useful information about their analytical performance. For example, Bio-Rad offers a program whereby customer's daily QC results can be transmitted electronically to their central data management system, and the QC report can be retrieved and reviewed within minutes. Assays can be monitored for linearity. QC results can be compared with those from other customers using similar methods and equipment. Multiple assays can be compared side by side to detect shifts due to instru ment performance or reagent lot. Data can be retrieved for compliance with CLIA and ISO regulations. Vendors can customize a QC program, combining these elements to meet each individual lab's specific needs.
Laboratories of all sizes and scopes can best meet the needs of doctors and patients by taking advantage of the wide variety of modern QC materials and data analyses to control analytical error. To this end, QC vendors can be enlisted as a valuable and expert resource. They will work with labs to design a customized QC program to verify the accuracy and precision of analytical methods.
Betsy Donnelly has 30 years of experience as technologist, scientist and manager in clinical laboratory medicine and biotechnology.
Related medicine technology :
1. Choosing Lab Quality Management Software
2. Optimizing Quality Control Data Management
3. Controlling the Spread of Healthcare Associated Methicillin Resistant Staphylococcus aureus Requires Active Surveillance
4. Tight Glycemic Control in the ICU
5. Diagnosing Diabetes: Immediate HbA1c Results Improve Glycemic Control
6. When Volume Matters, Immunoassay Systems Deliver
7. Genetic Analysis Systems Enter the Clinical Mainstream
8. Immunoassay Systems - Your Laboratory Workhorse
9. Urinalysis Analyzers: Large Capabilities in Every Size Device