The SU-MP225 represents an economical alternative to the SU-MP285 and SU- MPC365. In 2002, production and design changes allowed us to produce this motorized manipulator as a more affordable alternative to the industry standard SU-MP285. While the SU-MP225 feature set is less comprehensive than the SU-MP285, it includes the most popular features with an efficient user interface. The mechanical design utilizes a miniature stepper motor and integral anti-backlash gear head. Pre-loaded ball bearing slides provide smooth movement throughout the 25 mm of travel. The controller uses low-noise, linear-drive output circuitry identical to that found in the SU-MP285. The methodology for mounting pipette holders and headstages used with the MP-285 has been maintained in the SU-MP225 to allow for cross compatibility.