Medical Research Council - London Institute of Medical Sciences

Now in our 12th year of bringing you beautiful imagery from biomedical science every day

Bundles of Joy

Understanding more about how chromosomes segregate as a cell divides

13 January 2023

Bundles of Joy

Breaking a cell exactly in half requires huge feats of tiny engineering. Hundreds of proteins oversee the process of mitosis – but arguably the most crucial job, separating the precious DNA, still holds a few mysteries. Here scientists using super-resolution microscopy watch as microtubules – somewhere between fishing lines and microscopic scaffolding – (highlighted in green) first reach out from opposite sides of the cell towards the DNA (purple). The tubules meet in a criss-cross network seen from two different angles (top and bottom rows, left). Later in mitosis (middle and right) the tubules form thick bundles that bridge the gap between the different sides of the cell as the DNA lines up in the centre. Researchers believe kinetochores, linkers between DNA and microtubules, help to coordinate these overlap bundles,, which in turn guide the overall machinery as it begins the careful job of pulling the DNA apart.

Written by John Ankers

Search The Archive

Submit An Image

What is BPoD?

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.

Read More

BPoD is also available in Catalan at with translations by the University of Valencia.