Fluorescence-based detection of immobilized IgG antibodies on conjugated protein G polypeptide spots.

(A) Schematic representation of antibody immobilization on protein G spots with (S-SMPB(+)) or without (S-SMPB(-)) covalent grafting of protein G polypeptide. (B) Spotted anti-CD31 or anti-CD144 antibodies detected through fluorophore-labelled anti-mouse antibodies as described in the last step of Fig 1. The protein G polypeptide concentration applied was 5.5 μM. (C) Successful immobilization of different primary antibodies on conjugated protein G polypeptide (S-SMPB (+)) based on the detection of fluorophore-labeled secondary antibodies added after protein G polypeptide and primary antibody immobilization. Surfaces without S-SMPB and/or without primary antibodies were used as negative controls. *P S3 Appendix.