Figure 5

Fluorescence spectroscopic monitoring of the separation process. (a) Tryptophan fluorescence from the supernatants during different magnetic washes in step II (Figure 3) where serum is removed. MPs and bound antigens are pelleted with an external magnet while serum is removed (red full line). The pellet is then resuspended in 1 ml buffer A and then pelleted again while the supernatant was removed (green full line). This washing procedure was repeated two more times (blue full line). Dashed lines show (for reference) dilutions of serum to 10% (red), 1% (green) and 0.1% (blue). (b) Tryptophan fluorescence from the solution before and after the conjugation between MPs and antibodies. Red line: emission from antibody sample before magnetic particles were added. Blue line: emission from the supernatant after conjugation reaction where magnetic particles and bound antibodies are pelleted using a magnet.