Antibody-conjugated paramagnetic nanobeads: kinetics of bead-cell binding

Int J Mol Sci. 2014 May 19;15(5):8821-34. doi: 10.3390/ijms15058821.


Specific labelling of target cell surfaces using antibody-conjugated paramagnetic nanobeads is essential for efficient magnetic cell separation. However, studies examining parameters determining the kinetics of bead-cell binding are scarce. The present study determines the binding rates for specific and unspecific binding of 150 nm paramagnetic nanobeads to highly purified target and non-target cells. Beads bound to cells were enumerated spectrophotometrically. Results show that the initial bead-cell binding rate and saturation levels depend on initial bead concentration and fit curves of the form A(1 - exp(-kt)). Unspecific binding within conventional experimental time-spans (up to 60 min) was not detectable photometrically. For CD3-positive cells, the probability of specific binding was found to be around 80 times larger than that of unspecific binding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies / chemistry*
  • Antibodies / immunology
  • CD3 Complex / immunology
  • CD3 Complex / metabolism
  • Flow Cytometry
  • Humans
  • Kinetics
  • Leukocytes, Mononuclear / cytology
  • Leukocytes, Mononuclear / immunology
  • Leukocytes, Mononuclear / metabolism
  • Lipopolysaccharide Receptors / immunology
  • Lipopolysaccharide Receptors / metabolism
  • Magnetite Nanoparticles / chemistry*
  • Particle Size
  • Spectrophotometry


  • Antibodies
  • CD3 Complex
  • Lipopolysaccharide Receptors
  • Magnetite Nanoparticles