In order to reach maximum sensitivity of luminescence assay, the volume of the injected sample and the volume of the linear flowcell has to be optimized. By increasing injected sample volume, while using sandwich sequence protocol, it was found that similarly as in the GLOCELL experiment the plateau is reached at Sv= 100 mcrL, when using 14cm long flowcell (A, B). As to the linear flowcell volume, it would appear that it should be maximized. Since the volume of the linear cell increses with its length, the sample volume experiment was repeated with three flow cells (14cm = 70mcrL, 7cm= 35mcrL, 5cm= 25mcrL. It turns out, however, that while 7cm cell has 50% higher output than 5cm cell, the 14 cm cell has output 20% lower than 7cm flow cell, probably due to loss of light in the longer conduit (B).
The calibration experiments with 7cm long cell (C,D) show excellent reproducibility, with linear response up 100 microM NaClO. This calibration range can be extended upwards by decreasing the injected sample volume and by increasing concentration of luminol. The detection limit is estimated at 0.8micro M NaClO (E).
Performance of the Linear Flowcell
2.3.13.A.
