Practical Recommendations for the Selection and Use of Biochemical Kits in Laboratory Settings

Key factors to clarify before selecting a biochemical reagent kit

When selecting a biochemical reagent kit, laboratories should first confirm its intended use, applicable sample types, and compatible instrument platforms. Different biochemical analyzers differ in sample volume, incubation temperature, cuvette light path, and reading time, and the performance of the same biochemical reagent kit on different systems may not be completely consistent. It is recommended to check the applicable instrument models, sample types, and reference interval information in the reagent instructions, and conduct a comprehensive evaluation in combination with the common sample volume, testing throughput, and storage conditions of the department. For newly introduced projects, quality control materials and a small number of clinical samples can first be used for preliminary testing to observe whether precision, open-bottle stability, and calibration curves meet routine needs.

Open-bottle verification and storage and transport management

After a biochemical reagent kit arrives, the lot number, expiration date, and arrival temperature should be recorded, and it should be stored under refrigeration or protected from light as required. When opening the bottle for use, the open date should be marked on the bottle, and the open-bottle shelf life recommended in the instructions should be followed. For reagent components that are prone to moisture absorption or oxidation, the cap should be tightened immediately after use to avoid prolonged exposure to air. If the laboratory has a long usage cycle, small-package specifications or formulations with better open-bottle stability may be preferred. During transport, severe shaking and sudden temperature changes should be avoided. Cold-chain monitoring is especially important in winter and summer to prevent performance degradation of reagents under extreme temperatures.

Establish an internal quality control scheme matched to the reagent kit

Internal quality control is an important means of determining whether a biochemical reagent kit is stable in daily use. Laboratories should select quality control materials with a matrix close to that of human samples and set at least two concentration levels, covering the normal and abnormal ranges respectively. The quality control frequency can be set according to testing volume, reagent stability, and instrument status. If results show continuous drift or exceed commonly used rules, sample testing should be suspended and the cause investigated. Common problems include reagents being open for too long, carryover contamination from sampling probes, errors in reconstitution of calibrators, deviation in incubation temperature, and incorrect placement of reagent bottles. By plotting quality control charts and combining them with daily maintenance records, hidden risks in the use of biochemical reagent kits can be identified more promptly.

Reduce bias caused by operational and sample factors

Sample collection, centrifugation, and storage have a direct impact on the test results of biochemical reagent kits. Hemolyzed samples may interfere with some enzymatic or colorimetric assays, lipemic samples may cause increased turbidity or light-scattering interference, and icteric samples may affect absorbance measurement at specific wavelengths. Laboratories should establish clear sample acceptance criteria, annotate obviously abnormal samples, and indicate them in reports. During operation, attention should also be paid to the order of adding reagents and samples, mixing methods, and reaction time to avoid interference from bubbles, fibrin clots, and other factors. Only by incorporating the selection, storage, quality control, and operation of biochemical reagent kits into standardized procedures can the stability and credibility of test results be improved.