The CLSM described here can be built with relatively little electronic or optical experience and with a budget of approximately $20,000-$30,000 (excluding microscope and table). This cost is substantially less than that of commercial counterparts. However, this CLSM has excellent spatial and temporal resolution and the convenience of digital recording and playback. By building the CLSM, the investigator ensures long-term support and reliability of the instrument as well as the potential for future modifications and improvements. Finally, the sense of accomplishment of building your own instrument should not to be underestimated.