Evaluation of the ability of commercial disinfectants to degrade free nucleic acid commonly targeted using molecular diagnostics

Polymerase chain reaction (PCR) is an essential tool for rapid detection of pathogens, but is susceptible to cross-contamination by residual nucleic acid, leading to false-positive results. Adequate surface decontamination would help prevent this, but most protocols target infectious microbes rather than free nucleic acid. The aim of this study was to evaluate the ability of commercial surface disinfectants to degrade different representative classes of nucleic acid. Commercial surface disinfectants with various active ingredients, as well as 10% chlorine bleach, were tested. Nucleic acid was dried on to stainless steel coupons and treated with disinfectant for 0–4 min prior to neutralization and quantification by quantitative reverse transcription PCR. The effective disinfectants were also evaluated in the presence of organic load. Only dilute chlorine bleach and the hypochlorite-based commercial disinfectant significantly degraded any type of free nucleic acid. Hydrogen-peroxide- and quaternary-ammonium-based disinfectants gave