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Updated: Aug 10, 2026
07:38
Measuring In Vitro ATPase Activity for Enzymatic Characterization
Published on: August 23, 2016
Proficiency testing of enzymes. Charting the way toward standardization
J A Lott1, D W Tholen, C G Massion
1Department of Pathology, The Ohio State University, Columbus 43210-1228.
Archives of Pathology & Laboratory Medicine
|April 1, 1988
Summary
The College of American Pathologists Enzyme Survey (ES) found varied enzyme measurement results due to diverse lab methods. Long-term enzyme testing stability needs improvement from suppliers and labs, but proposed CV goals are achievable.
Area of Science:
- Clinical Chemistry
- Laboratory Medicine
- Biochemical Analysis
Background:
- Laboratories utilize diverse analytical methods for enzyme measurements, leading to significant result variability.
- The College of American Pathologists Enzyme Survey (ES) monitors the quality of enzyme testing across numerous laboratories.
- Assessing both short-term and long-term variability in enzyme testing is crucial for clinical diagnostics.
Purpose of the Study:
- To evaluate the variability of enzyme measurements in clinical laboratories participating in the College of American Pathologists Enzyme Survey.
- To assess the impact of a new reference material on reducing data variability for aspartate aminotransferase measurements.
- To propose achievable quality goals for short-term and long-term coefficients of variation in enzyme testing.
Main Methods:
- Analysis of data from the College of American Pathologists Enzyme Survey over a ten-year period.
- Determination of short-term (within-mailing) and long-term (between-mailings) coefficients of variation (CVs) for enzyme measurements.
- A special study involving a reference material (NBS RM 8430) with a certified aspartate aminotransferase value was conducted across peer groups.
Main Results:
- Short-term CVs in the ES have shown improvement over ten years, but long-term stability requires further effort from manufacturers and labs.
- Correction of results to the NBS RM 8430 aspartate aminotransferase value reduced data range for some instruments (duPont aca) but not others (KDA, SMAC).
- Proposed goals of 5% for short-term CV and 10% for long-term CV are achievable and meet clinical biochemical screening needs.
Conclusions:
- Long-term stability in enzyme testing remains a challenge, necessitating collaborative efforts from reagent/instrument suppliers and participating laboratories.
- The availability of reference materials like NBS RM 8430 offers potential for improving consistency in specific enzyme measurements.
- Established quality goals for enzyme testing CVs are practical and align with the clinical utility of biochemical screening data.
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