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Validation of the Coulter LH 750 in a hospital reference laboratory
C Aulesa1, I Pastor, D Naranjo
1Laboratories Unit, Valle de Hebron Hospital Complex, Barcelona, Spain. 27215cam@comb.es
Insights
The Coulter LH 750 analyzer demonstrates excellent analytical quality and practical usability for routine hemogram analysis. Its validation shows high precision and accuracy, with notable performance in erythroblast counting and differential analysis.
Area of Science:
- Clinical Hematology
- Laboratory Medicine
- Diagnostic Instrumentation
Background:
- Central hospital laboratories process high volumes of hemograms daily.
- Reference laboratories require validated, high-quality diagnostic instruments.
- Previous generations of analyzers (e.g., Coulter Gen-S) set performance benchmarks.
Purpose of the Study:
- To validate the analytical quality and practical utility of the Coulter LH 750 hematology analyzer.
- To assess the performance of new features, including erythroblast counting.
- To evaluate the analyzer's suitability for routine use in a high-volume laboratory setting.
Main Methods:
- Analytical quality assessment using reference controls and patient specimens.
- Evaluation of imprecision, inaccuracy, linearity, and interference effects (bilirubin, lipemia, hemolysis, etc.).
- Correlation studies with existing methods (Coulter Gen-S, manual reference) and assessment of flagging systems.
Main Results:
- Excellent within- and between-run imprecision (0.24%-2.56%) and inaccuracies (-1.32%-3.07%) for basic hemogram parameters.
- Linearity demonstrated across wide ranges for leukocytes and platelets.
- The new erythroblast count feature showed acceptable imprecision (10%-12% with controls, 10.39% with patient samples).
Conclusions:
- The Coulter LH 750 analyzer meets rigorous analytical quality standards for routine hematology.
- The instrument offers practical advantages in speed, cost, and software features for laboratory workflow.
- Introduction of the LH 750 is expected to yield significant improvements in laboratory operations.
Abstract:
Validation of the Coulter LH 750 was carried out in our central hospital laboratory, which processes 1500 hemograms per day for patients admitted into the 4 hospitals of our hospital complex and their corresponding outpatient departments. It is the reference laboratory for the provincial health care area. The analytical quality and the practical use of the instrument were studied, and we obtained within- and between-run imprecision estimates with reference controls of between 0.24% and 2.56% and inaccuracies of between -1.32% and 3.07% for basic hemogram parameters. Similar results were obtained with specimens from patients, with imprecision estimates between 0.56% and 2.56%. Linearity estimates were between 0.3 x 10(9)/L and 380 x 10(9)/L for leukocytes and between 3 x 10(9)/L and 1900 x 10(9)/L for platelets. The instrument evaluation was completed with a study of interference by bilirubin, lipemia, hemolysis, platelet clumps, and heparin and an examination of other variables, including carryover, detection limits, and the correlation of results with those of the Coulter Gen-S. A special evaluation was made of the new erythroblast count feature; with reference controls, imprecision estimates for this count were 10% to 12%, and with patient specimens imprecision averaged 10.39% up to 4 erythroblasts per 100 leukocytes. We also studied the correlation of LH 750 results and interferences with those of the manual reference method. Finally, National Committee for Clinical Laboratory Standards protocols were used to test for suspect and confirmation flags in leukocyte differential counts for 258 specimens representative of our routine. The practicability of the analyzer was studied in terms of technical difficulty, speed, and cost; also evaluated were new software elements for validation by source clinic and pathology and for reference values based on age. In conclusion, we analyzed the impact and improvements that may be expected in our laboratory (a user of Technicon and Coulter instruments) from introducing the new LH 750 analyzer into our routine.