Comparative studies on the microbiological vitamin B12 assay at two laboratories

Area of Science:

• Microbiology
• Analytical Chemistry
• Nutritional Science

Background:

• Microbiological assays are crucial for determining vitamin B12 levels.
• Standardization of assay methods is essential for reliable results.
• Turbidimetric methods are commonly employed for vitamin B12 quantification.

Purpose of the Study:

• To compare routine turbidimetric methods for vitamin B12 microbiological assay between two laboratories.
• To assess the agreement of vitamin B12 content determination for various products.
• To evaluate the impact of standardized assay components on result consistency.

Main Methods:

• Comparative analysis of turbidimetric microbiological assays for vitamin B12.
• Standardization of key assay parameters including assay design, test strain (Lactobacillus leichmannii), medium, and reference standard.
• Determination of vitamin B12 content in five different products over a 6-year period.
• Independent assay execution at two distinct laboratories.

Main Results:

• Four out of five products analyzed showed a satisfactory agreement in vitamin B12 content determination (difference < 5%) between the two laboratories.
• Despite variations in assay procedures, the methods yielded comparable results for most products.
• The study highlights the robustness of turbidimetric assays when key parameters are controlled.

Conclusions:

• Turbidimetric microbiological assays for vitamin B12 can provide reliable and comparable results between different laboratories.
• Standardization efforts contribute to achieving a satisfactory degree of agreement in vitamin B12 quantification.
• The findings support the use of these methods for routine vitamin B12 analysis in various products.