SummaryRhinovirus strains representative of the 55 numbered serotypes and one subtype were tested in HeLa and WI-38 cell culture tubes for inhibition by 223 and 447 μM concentrations of 2-(α-hydroxybenzyl)-benzimidazole (HBB) and 77, 115, 192, 383, and 574 μM concentrations of D - (-) − 2 - (α - hydroxybenzyl) - benzimidazole · HCl (D-HBB · HCl). Half of strains tested showed some inhibition at a 447 μM concentration of HBB and strains of all types except 1A and subtype 1B showed some degree of inhibition at a D-HBB · HCl concentration of 574 μM or less. An increasing proportion of strains were inhibited as test concentrations of the compounds were increased. Multiple strains of rhinovirus types 7 and 24 showed similar degrees of sensitivity to a 192 μM concentration of D-HBB · HCl. Comparative testing of strains of 36 types vs a 192 μM concentration of D-HBB · HCl in WI-38 and HeLa cell culture tubes gave similar but not identical results. D-HBB · HCl concentrations of 574 and 383 μM were toxic for cells...