Aim of our study is to use Atomic Force Microscopy (AFM) to measure the spring constant for
single bovine serum albumin (BSA) ‘ polyclonal antibody to BSA (Ab-BSA) complex (kcomplex)
as a function of pulling off force and complex extension. By the combination of AFM operated in
the force-spectroscopy mode with the small dithering of the AFM tip we are able to detect the
change of the dithering amplitude upon the pulling off process and to derive the value of kcomplex.
At the moment of single specific bond rupture the spring constant value of 0.017 ± 0.003 N/m is