Publications

We have performed single-chain observation by fluorescence microscopy on T4 DNAs complexed with maltosylated amino-pendant polyethylene glycol (mal-PEG-A) in the presence of sodium dodecyl sulfate(SDS). With 0.02mM mal-PEG-A/SDS ([NH]=[SDS]=0.02mM). individual DNAs existed as either a compact globule state or a partially unfolded globule state. Aggregates between multiple number of DNA chains are formed at higher concentrations of mal-PEG-A/SDS. With 1 mM mal-PEG-A/SDS, the DNAs take an elongated coil conformation. It was found that the aggregate with multiple DNAs changes its morphology markedly during the focused illumination of 400-500 nm light. Such a morphological change of the complex has been discussed in relation to the ability of SDS micelle to anchor the DNA fragments induced by the cutting with photo-illumination.