The BioStack3 microplate stacker features a dual-plate carrier and rotational wrist to move plates from the source stack to the instrument and back to the destination stack, keeping two plates in process. BioStack3 is designed to provide increased throughput for batched processes. BioStack3 can remove one plate from an instrument carrier and replace it with another microplate in less than 10 seconds. The BioStack3 also features a choice of 10, 30, or 50 microplate storage stacks, and maintains a small footprint for use in a biosafety cabinet or hood.