Assessment of the lysis efficiency of selected guanidinium thiocyanate/hydrochloride lysis buffers commonly used in PCR diagnostics

Abstract

In this study, the virucidal activities of Qiagen Buffer AL, Qiagen Buffer AVL and Roche MPLB (MagNA Pure lysis/binding) buffer, each containing a guanidine-based denaturing agent, were assessed against selected pathogenic animal (canine adenovirus type 2 (CAV-2), 6.0 log₁₀ TCID₅₀/mL and canine coronavirus (CCoV), 3.9 log₁₀ TCID₅₀/mL) and human (hepatitis A virus (HAV), 6.7 log₁₀ TCID₅₀/mL) viruses at different temperatures and over different times. In the virus inactivation experiments, all three lysis buffers were able to inactivate CAV-2 and CCoV even in a short 1-min contact time. Although the HAV titre was reduced by at least 4.5 log₁₀, it was still observed to have residual infectivity. Only the AL lysis buffer in conjunction with heat treatment appeared to be highly efficient at HAV inactivation. A complete (99.99 %) inactivation of CAV-2 (6.0 log₁₀ TCID₅₀/mL) and CCoV (4.7 log₁₀ TCID₅₀/mL) by the MPLB buffer was also observed even at lower-than-recommended buffer concentrations. Generally, all lysis buffers were effective in the inactivation of enveloped and non-enveloped animal viruses. However, they reduced HAV infectivity to a lesser extent, indicating a need for a more stringent inactivation method to destroy infectivity of this virus in diagnostic material.