Automatic determination of malate dehydrogenase activity with a flow-injection multidetection system

Area of Science:

• Biochemistry
• Analytical Chemistry
• Enzyme Assays

Background:

• Malate dehydrogenase (MDH) is a crucial enzyme in metabolic pathways.
• Accurate and efficient determination of MDH activity is vital for clinical diagnostics and biochemical research.
• Existing methods may lack automation or require complex sample handling.

Purpose of the Study:

• To develop and validate an automatic flow-injection analysis (FIA) method for determining malate dehydrogenase (MDH) activity.
• To assess the method's sensitivity, precision, and applicability to biological samples.
• To provide a rapid and reliable tool for MDH activity quantification.

Main Methods:

• A flow-injection manifold was designed, incorporating a selecting valve for continuous reagent circulation.
• The system utilized a conventional spectrophotometer with a flow-cell integrated into a closed circuit.
• Multi-peak recordings were generated for each sample passage, allowing flexible sensitivity adjustments.

Main Results:

• The developed FIA method accurately determined MDH activity in the range of 0.02–2.00 U/l.
• The method demonstrated high precision with a relative standard deviation (r.s.d.) of less than 0.90%.
• Analyte recoveries in human serum samples ranged from 96% to 103%, indicating good applicability.

Conclusions:

• The proposed automatic flow-injection method provides a sensitive, precise, and efficient approach for MDH activity determination.
• The method's adaptability and validated performance in human serum samples highlight its potential for routine analysis.
• This FIA system offers a valuable advancement for biochemical and clinical laboratories.