Chromosomes contain both DNA and proteins used to read the “blueprint” for life in our cells. Chromosomes and DNA have both been studied extensively for more than a century but the mass of 46 human chromosomes had not been measured until now.
University College London (UCL) researchers measured the mass of human chromosomes using powerful X-rays at Diamond Light Source, the United Kingdom’s national synchrotron facility. Using X-ray ptychography, researchers created a highly sensitive 3D reconstruction of a spread of 46 chromosomes in metaphase.
The study found that the chromosomes weighed 242 picograms in total, about 20 times heavier than DNA alone. The results were published in Chromosome Research.
“This is heavier than we would expect, and, if replicated, points to unexplained excess mass in chromosomes,” said Ian Robinson, senior author and professor in the London Centre for Nanotechnology at UCL.
The study of chromosomes has important implications for human health. Improvements in chromosome imaging and measurement can aid in medical research to diagnose cancer and other diseases.
Photo: The spread of 46 human chromosomes measured using X-rays in the study, with color added. Credit: Archana Bhartiya et al/Chromosome Research