Thiamine HCl — 5 g

An essential B-vitamin cofactor included in most tissue culture media (MS, B5) at 0.1–1.0 mg/L. Supports cellular metabolism, particularly oxidative decarboxylation reactions. Partial degradation (~20%) occurs during standard autoclaving at 121°C/15 min, which is acceptable at typical media concentrations. For sensitive protocols, filter-sterilize separately. Store stock solutions at -20°C to prevent degradation; protect from light.