Background: A method for the selection of suitable molecular
recognition element (MRE) for the quantification of human epidermal
growth factor (hEGF) using surface plasmon resonance (SPR) is
presented. Two types of hEGF antibody, monoclonal and polyclonal, were
immobilized on the surface of chip and validated for its
characteristics and performance in the quantification of hEGF.
Validation of this analytical procedure was to demonstrate the
stability and suitability of antibody for the quantification of target
protein. Results: Specificity, accuracy and precision for all samples
were within acceptable limit for both antibodies. The affinity and
kinetic constant of antibodies-hEGF binding were evaluated using a 1:1
Langmuir interaction model. The model fitted well to all binding
responses simultaneously. Polyclonal antibody (pAb) has better affinity
(KD = 7.39e-10 M) than monoclonal antibody (mAb) (KD = 9.54e-9 M).
Further evaluation of kinetic constant demonstrated that pAb has faster
reaction rate during sample injection, slower dissociation rate during
buffer injection and higher level of saturation state than mAb.
Besides, pAb has longer shelf life and greater number of cycle run.
Conclusions: Thus, pAb was more suitable to be used as a stable MRE for
further quantification works from the consideration of kinetic, binding
rate and shelf life assessment