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

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.