pFI in Lab-on- valve Format:
Incubation during stop flow period
Stopping the flow is powerful tool designed to allow chemical reactions to proceed, while dilution of the reaction product that would be caused by forward flow, is avoided. Trapping the reacting mixture in a holding coil or flow cell provides a suitable period for incubation. Capturing reactants in a flow cell allows monitoring of reaction rate in real time.
The movie clips demonstrate the Stop in Holding Coil (SHC) technique and the Stop in Flow Cell (SFC) technique by using enzymatic assay of glucose as a model system. The method is based on a two reaction producing red quinoeminine dye that can be monitored at 500nm. ( 1.2.33.)
1.2.25.B.
The gradual formation of red dye in the holding coil during stop flow period is followed by rapid washout of the coil by accelerated flow that brings reaction product through a flow cell.
Stopping the flow while a sample is in the flow cell, allows monitoring of reaction rate. The movie clip shows transport of reaction mixture into flow cell and gradual formation of the red dye , followed by rapid washout at the end of monitoring period. (1.2.33.)