A low-cost automated focusing system for time-lapse microscopy

Abstract

We present a flexible, low-cost system for maintaining image focus during time-lapse and video microscopy, where focus drift over time can be problematic. The system comprises a stepper motor controlled by software which maintains focus in a closed-loop feedback arrangement using an image analysis approach which quantifies the amount of detail in the image. The focusing attachment is not microscope specific and comprises components totalling less than 200 GBP.