Image based instrument viability controls. Our particle standards offer discrete "live" and "dead" populations. They can be delivered in customizable ratios & concentrations. ViaCheck™ Viability Control 50% is a mixed suspension of microspheres that simulates a 50:50 ratio of live and dead (or dying) cells stained with Trypan Blue. ViaCheck™ SingleShots™ minimize error and maximize efficiency by circumventing potential human error from repeated bottle resuspension & pipetting steps. BLI20BS is the SingleShot equivalent to 20mL Cat. # 24623. Supplemental ViaCheck™ Literature