Quality control in the microbiological serum folate assay.

Area of Science:

• Clinical Chemistry
• Microbiology
• Analytical Biochemistry

Background:

• Microbiological assays for serum folate are crucial for diagnosing deficiencies.
• Antibiotic contamination is a common issue, leading to falsely low folate values.
• Existing methods lack consistent detection of antibiotic interference.

Purpose of the Study:

• To modify the serum folate microbiological assay for reliable detection of antibiotic contamination.
• To investigate other variables affecting assay accuracy.
• To develop a quality control system for consistent assay performance.

Main Methods:

• Modification of the standard microbiological assay for serum folate.
• Investigation of assay parameters and potential interfering substances.
• Implementation of a quality control system for batch assessment.

Main Results:

• The modified assay consistently identifies the presence and extent of antibiotic contamination.
• A quality control system effectively detects assay inconsistencies.
• Clinically useful results can be reported from some imperfect assay batches, reducing repeat testing.

Conclusions:

• The enhanced assay and quality control system improve the reliability of serum folate testing.
• Accurate detection of antibiotic interference is essential for valid folate measurements.
• The system minimizes the need for re-assaying samples with minor contamination.