Untitled

This clip demonstrates the merging of sample with diluent at a confluence point situated at the central port in two line SIA system. The sequence shows aspiration of 100 microliters of blue dye from sample port into holding coil #1. Next, the valve is turned towards the diluent port and while 200 microliters are aspirated at a rate of 50 microliters/second into HC#2, 100 microliter the blue sample zone is pushed from HC#1 at the flow rate of 25 microliters/second, thus forming 1:1 sample/diluent mixture in holding coil#2. Next valve is turned towards the flow cell, flow is reversed and the diluted sample zone is passed through the flow cell. Finally the system is flushed with a burst of rapid flow.

Note that during sample and diluent aspiration in 1:1 stream merging mode into the holding coil #2, the mixing is incomplete while the dye retreats into the holding coil. However, when the flow is reversed, the dye zone emerging from holding coil #2 is mixed, forming a well mixed concentration gradient.