Handling and analysis of 5-formyl-, 5,10-methenyl-, 10-formyl-, 5-formimno-, and 5,10-methylenetetrahydrofolates

As the principal one-carbon carriers in mammalian biology, tetrahydrofolates are crucial for normal and malignant cells to synthesize and repair DNA and are the target of extensive research, including metabolomics analysis. The susceptibility of tetrahydrofolates to oxidization, as well as the propensity of substituted tetrahydrofolates to chemical degradation, mandates the use of carefully controlled experimental conditions to ensure their integrity. Analytical protocols for LC analysis along with handling and storage conditions for 5-formyl-, 5,10-methenyl-,10-formyl-, 5-formimno-, and 5,10-methylenetetrahydrofolate are described.