The ability to rapidly and reliably genotype mice is an important concern. Traditional methods employ labour intensive and time consuming techniques such as test crossing, gel electrophoresis or nucleic acid hybridization. Here we show that a new molecular biology workstation, the WAVE TM DNA Fragment Analysis System, can easily resolve polymerase chain reaction (PCR) products that have small differences in their lengths. Analysis is fully automated and takes less than 7 min per sample. Approximately 200 samples can be analysed per day with only minutes of hands-on time after completion of the PCR. Genotyping with the WAVE TM DNA Fragment Analysis System is a fast and efficient method with minimal manual intervention.