Interactions of nanoparticles with body proteins - improvement of 2D-PAGE-analysis by internal standard

Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) is the method of choice to investigate protein adsorption of blood proteins (opsonization ) onto nanoparticular drug carriers. In general the reproducability of the obtained adsorption patterns is satisfying. However, direct comparison betw een the amounts of single protein spots from gels obtained in different run s is difficult, because 2D-PAGE is a multistep procedure. A possible soluti on of the problem is to establish a protein as internal standard. Therefore , selected proteins (Bio-rad) were under investigation. Due to its molecula r weight and isoelectric point, soybean trypsin inhibitor (TI) does not int erfere with plasma components. Therefore, a method was established to use T I as an internal standard protein to improve comparability between the 2D-P AGE gels obtained in different analytical runs. (C) 2000 Elsevier Science B .V. All rights reserved.