HA assay of T3D σ1 point mutants.

<p>Purified reovirus virions (10¹¹ particles) were serially diluted in 0.05 ml of PBS in 96-well U-bottom microtiter plates. Bovine erythrocytes were washed twice with PBS and resuspended at a concentration of 1% (vol/vol) in PBS. Erythrocytes (0.05 ml) were added to wells containing virus and incubated at 4°C for at least 2 h. HA titer is expressed as 10¹¹ particles divided by the number of particles/HA unit. One HA unit equals the number of particles sufficient to produce HA. <b>*</b>, <i>P</i><0.05 in comparison to T3D (Student's <i>t</i> test).