L-Arginine Hydrochloride Enables Cold-Chain-Free DNA Polymerase Storage

Preserving DNA polymerases under ambient conditions is a critical challenge, particularly in resource-limited settings with minimal cold storage infrastructure. This study introduces a novel, cost-effective approach to polymerase stabilization using L-arginine hydrochloride (LAH), evaluating its efficacy for Pfu polymerase and polymerase mixtures stored in 20 µl aliquots at 4°C, 25°C, and 37°C over three months. Enzyme activity was assessed via polymerase chain reaction (PCR) amplification of a 1250 base pair (bp) DNA fragment. Pfu polymerase maintained enzymatic activity at all tested temperatures with 1 M LAH, whereas activity was lost at 37°C without the stabilizer. LAH also enhanced the stability of Taq polymerase and Pfu + Taq mixtures, though with reduced efficacy. Mechanistically, LAH prevents protein aggregation, enhances solubility, and stabilizes enzyme structure through electrostatic interactions. These findings position LAH as a robust stabilizer, reducing cold chain dependency and enabling scalable molecular diagnostics in low-resource environments. This study advances enzyme preservation by offering a sustainable alternative to traditional methods, with applications in clinical diagnostics and biotechnology. Future work will optimize LAH concentrations, assess long-term stability beyond three months, and extend the approach to other thermostable polymerases.