Optical speckles of blood proteins embedded in porous glassy substrate

Blood protein molecules could be embedded in porous glassy substrate with 10-nm pores. The embedding principle is based on blood cell dehydration with the destruction of the cell membrane, and reconstitution and centrifuge could yield a suitable solution for doping into a porous glassy medium. The doped glassy substrate speckle pattern under laser illumination could be used to characterize the protein size distribution. Calibration with known protein embedded samples would result in an optical procedure for the characterization of a blood sample. Samples embedded with larger kilo-Dalton protein molecule show more variation in the speckle patterns, consistent with protein folding interaction inside a pore cavity. A regression model has been used to correlate the protein molecule sizes with speckle sizes. The use of diffusion mean free path information to study protein folding in the embedding process is briefly discussed.