Hi-Di Formamide (25 mL)

Enzovera Hi-Di Formamide (EV-SGR-011) is high-purity, deionized formamide for resuspension of purified Sanger sequencing products prior to capillary electrophoresis injection. It denatures DNA secondary structure during the heat-denaturation step that precedes injection, ensuring that sequencing fragments enter the CE capillary in a fully single-stranded, fully denatured state for optimal resolution. The product meets ABI Hi-Di Formamide performance specifications and is supplied in 25 mL bottles.

Function in CE injection. After cleanup, purified sequencing extension products are resuspended in Hi-Di Formamide and heat-denatured (typically 95°C for 3–5 minutes followed by snap-chill on ice). The formamide disrupts intra- and inter-strand hydrogen bonds, preventing the re-annealing and secondary structure formation that would otherwise occur as the sample cools to injection temperature. Fully denatured single-stranded fragments enter the CE capillary uniformly under the applied electrokinetic injection, producing tight peak shapes and accurate base calling across the full read range.

Purity specifications. The Hi-Di formulation is deionized to remove ionic contaminants (organic acids, formate breakdown products, residual cations) that would otherwise compete with DNA for injection into the capillary or contribute to baseline noise. Purity is validated by conductivity testing and by side-by-side CE injection performance comparison against reference ABI Hi-Di Formamide. The product is supplied in opaque or amber bottles to prevent UV-induced decomposition during storage.

Handling and stability. Formamide is hygroscopic and absorbs water and atmospheric carbon dioxide on prolonged exposure to air, generating formate and ammonium ions that degrade CE injection performance. Aliquot into single-use volumes (1–2 mL) upon receipt and store at −20°C in tightly capped tubes. Discard aliquots that have been thawed and re-exposed to atmosphere — the conductivity rises sharply within hours of opening. Single-use aliquot practice is the single most important factor in maintaining consistent CE injection performance over time.

Recommended applications:

• Resuspension of cleaned Sanger sequencing extension products before CE injection
• Denaturation buffer for ssDNA fragment analysis (STR, microsatellite, MLPA)
• Sample preparation for all ABI Genetic Analyzer capillary electrophoresis runs
• Resuspension of size standards (LIZ, ROX, GeneScan markers) for CE injection

Pack size: 25 mL bottle. Store at −20°C in tightly capped single-use aliquots. Safety: Formamide is a reproductive toxin. Handle in a fume hood with appropriate PPE (gloves, lab coat, eye protection). Refer to the Safety Data Sheet for complete handling, exposure limit, and disposal information.