Automated enzymatic method for determining ammonia in plasma, with 14-day reagent stability

Area of Science:

• Clinical Chemistry
• Biochemistry
• Analytical Chemistry

Background:

• Accurate plasma ammonia measurement is crucial for diagnosing hyperammonemia.
• Current enzymatic assays often suffer from limited reagent stability and high costs.

Purpose of the Study:

• To develop and validate a cost-efficient, automated enzymatic method for plasma ammonia determination.
• To enhance reagent stability for routine clinical laboratory use.

Main Methods:

• An automated enzymatic assay for ammonia was developed.
• Reagent stability was assessed at 4 degrees C.
• The method was validated against the Du Pont aca method using a Cobas-Fara analyzer.
• Precision was evaluated through within-run and day-to-day studies.

Main Results:

• Reagents demonstrated stability for at least 14 days at 4 degrees C, significantly longer than conventional methods.
• The automated method showed good correlation with the Du Pont aca method.
• Excellent within-run and day-to-day precision were achieved across a wide concentration range.
• The standard curve remained linear up to 1000 mumol/L.

Conclusions:

• The developed automated enzymatic method provides a stable, cost-effective, and precise alternative for plasma ammonia analysis.
• This method is adaptable to various automated analyzers, offering flexibility for clinical laboratories.