Nucleic Acids Research, 2000, Vol. 28, No. 2 593-596
© 2000 Oxford University Press
Conformational transition in DNA on a cold surface
Department of Physics and Astronomy, 1Department of Chemistry and Biochemistry and 2Department of Microbiology, Arizona State University, Tempe, AZ 85287-1504, USA
The contour length of DNA fragments, deposited and imaged on mica under buffer, was measured as a function of deposition temperature. Extended DNA molecules (on Ni- and silane-treated surfaces) contract rapidly with falling temperature, approaching the contour length of A-DNA at 2°C. The contraction is not unique to a specific sequence and does not occur in solution at 2°C or on a surface at 25°C, indicating that it arises from a combination of low temperature and surface contact. It is probably a consequence of reduced water activity at a cold surface.
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