A Robotic Microscope for 3D Imaging Early Stage Salamander Embryos

Abstract

A robotic microscope was designed using a microcontroller with three stepper motors to control three-axis movement. Two 7 megapixel digital cameras controlled by the microcontroller capture images when the stage moves into position. Using 4 prisms, through-focus time-lapse digital pictures of six views of Ambystoma mexicanum embryos (axolotl, a salamander) are taken every 5 minutes for 52 hours of early development, from fertilization to stage 20, i.e., neural tube closure. In-focus views of all sides of the embryo are calculated using several image fusion techniques. In the early embryo surface epithelial cells differentiate to form neural tissue and external skin tissue. Observing the whole embryo surface at cellular level will give a better idea of the stress and strain each cell undergoes and physical forces involved in cell differentiation, including waves of cell surface expansion or contraction Time-lapse photographs capture the dynamics of the embryo during development, that is lost in histological techniques that use non-living material.