Flow immunochemical bio-recognition detection for the determination of Interleukin-10 in cell samples

On- and off-line heterogeneous non-competitive flow immunoassays for the de termination of Interleukin-10 are described. The sample containing IL-10 is mixed, either on-line in a reaction coil or off-line in a test tube, with fluorescent labelled anti-IL-10 antibodies to form an antibody-antigen comp lex. The labelled unbound antibodies are trapped on an immobilized IL-10 co lumn whereas the IL-10-antibody complexes are eluted and detected downstrea m by a fluorescence detector. The optimization of the systems was performed with respect to choice of affinity support, flow rate, carrier buffer addi tives, pH and antibody-antigen association. Both bio recognition assays wer e tested with a spiked cell medium and the IL-10 detection limits in this m atrix was found to be 8 fmol using the off-line incubation mode and 40 fmol using the on-line incubation mode. The sample through-put was 26 and 40 sa mples per hour in the on-line and off-line incubation modes, respectively. IL-10 identification in the sample fractions was achieved using MALDI-TOF M S. (C) 2000 Elsevier Science B.V: All rights reserved.