Nature Communications published the work with the leading participation of the team from the Nencki Institute, led by Prof. Grzegorz Wilczyński. The publication entitled "Ultrastructural visualization of 3D chromatin folding using volume electron microscopy and DNA in situ hybridization" concerns a new method of chromatin analysis within the cell nucleus. Chromatin is a complex of DNA and specific proteins. What is really fascinating, is that the human DNA chain, being around 2 m long, is created by interactions with proteins (mainly so-called histones), which are packed into a nucleus of around 10 micrometers in size (an amazing degree of compression, exceeding 200,000 times). Therefore, scientists say that the laws governing the packaging of chromatin can have a significant impact on gene expression, and thus, on the protein composition of the cell. Biochemical studies show that chromatin fragments can physically interact with each other, but there are still images which show in detail, the shape of chromatin. The achievement of the Polish team, in collaboration with a group led by Prof. Yijun Ruan, from Jackson Laboratories for Genomic Medicine, USA, was to compare real three-dimensional images of chromatin in several hundred human cells (Prof. Wilczyński's team), with biochemical predictions based on an average multi-cell study (with Prof. Ruan’s team). The correlation of results showed the compatibility of microscopy with biochemistry.

The core merit of the group from the Nencki Institute, was the development and application of electron microscopy for imaging chromatin domains, with a resolution of up to 10 times greater than approaches based on the latest achievements of light microscopy. This microscopic approach has never been used before.

Full text of publication is available at: https://www.nature.com/articles/s41467-020-15987-2