Single-molecule mechanical fingerprinting of DNA and peptides with DNA nanoswitch calipers

Amazing stuff!

"... Proteins are much more complex than DNA and RNA, and are often chemically modified, making the goal of easily identifying single proteins within a sample (single-molecule proteomics) challenging to achieve. ..."

From the abstract:

"Decoding the identity of biomolecules from trace samples is a longstanding goal in the field of biotechnology. Advances in DNA analysis have substantially affected clinical practice and basic research, but corresponding developments for proteins face challenges due to their relative complexity and our inability to amplify them. Despite progress in methods such as mass spectrometry and mass cytometry, single-molecule protein identification remains a highly challenging objective. Towards this end, we combine DNA nanotechnology with single-molecule force spectroscopy to create a mechanically reconfigurable DNA nanoswitch caliper capable of measuring multiple coordinates on single biomolecules with atomic resolution. Using optical tweezers, we demonstrate absolute distance measurements with ångström-level precision for both DNA and peptides, and using multiplexed magnetic tweezers, we demonstrate quantification of relative abundance in mixed samples. ..."

Fingerprinting proteins with force DNA Nanoswitch Calipers allow scientists to measure distances within single molecules, opening a new avenue for single-molecule proteomics

Single-molecule mechanical fingerprinting with DNA nanoswitch calipers (no public access, but article above allows access to PDF)