Finding out what goes on within individual cells is no easy task. It can involve freezing an organ and cutting it into super-thin slices for scanning by electron microscopy. These scans are then combined to produce a 3D reconstruction. However, this slicing technique cannot easily be used for thick, complex cells. It tends to result in distorted images because slices get squashed during the cutting process. Scientists have developed a solution, which instead of electrons, uses a focused beam of gallium ions. Firing the ions at a shallow angle into the tissue and using a computer program to reconstruct the data, researchers can produce highly detailed images like the one above of a slime mold cell. At the top is the nuclear membrane with pores (coloured blue) that separates the nucleus from the cytoplasm and its various organelles.
Written by Andrew Purcell
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.