Quantitative analysis of mammalian chromosome by scanning transmission soft X-ray microscopy

• Published in: Ultramicroscopy Vol. 194; pp. 1 - 6
• Main Authors: Shinohara, K, Ohigashi, T, Toné, S, Kado, M, Ito, A
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.11.2018
• Subjects: Animals; Cell Line; CHO Cells; Chromosomes, Mammalian - chemistry; Cricetulus; DNA - chemistry; Evaluation Studies as Topic; Microscopy, Electron, Scanning Transmission - methods; Nitrogen - chemistry; Proteins - chemistry; X-Rays
• ISSN: 0304-3991; 1879-2723
• DOI: 10.1016/j.ultramic.2018.07.001

•Quantitative mapping of DNA and protein in chromosome was carried out using STXM.•Analytical procedure was developed using NEXAFS at the N-K absorption edge.•The quantities of DNA and protein were obtained in the unit of pg per square microns.•The ratio of DNA to protein depends on the locations in chromosome. Soft X-ray spectromicroscopy was applied to study the quantitative distribution of DNA and protein in a mammalian chromosome at the spatial resolution of 100 nm. The quantities of DNA and protein were evaluated using 1s-π* transition in the NEXAFS spectra at the nitrogen K absorption edge. DNA was not uniformly distributed in the chromosome and DNA/protein ratio was less than 0.497. The present analysis revealed the clues to identify other molecules that contribute to the absorption spectrum of the sample. The results suggested that accumulation of the absorption spectra of relevant molecules would support the refinement of the analysis.