Formed by the integration of nanotechnology and biotechnology, nanobiotechnology is a new field that seeks to elucidate life phenomena using nano-level analysis technology and to apply the results to the fields of pharmaceuticals and electronics materials. Biopolymers such as DNA and proteins have particle diameters ranging from several to tens of nanometers. Essentially, these are nanomachines that control the phenomena associated with life. Evaluations of their physical properties often entail measurements of particle diameter, often using a dynamic light scattering method capable of measurement of several nm level.
We dissolved proteins of varying molecular weights – namely, bovine serum albumin (BSA, monomer Mw = 66,000), ovalbumin (OVA, Mw = 45,000), and lysozyme (Mw = 14,000) – in a 10 mM phosphate buffer solution (pH 7) to achieve a concentration of 1 mg/ml and performed measurements after optical purification (filtration through a filter with a pore size of 0.1 µm).


