Flow conduit system for a biochemical sensor

A flow conduit system suitable for biochemical sensing, the flow conduit system comprising,

• a first flow cell conduit comprising one or more sensing areas for biochemical sensing;
• a first selector valve;
• a second selector valve which is fluidly connected to the first flow cell conduit;
• a first inlet/outlet conduit which has a first end which is connected to the first flow cell conduit and a second end which is connected to the first selector valve, so as to fluidly connect the first flow cell conduit to the first selector valve;
• a first injection conduit having a first end and a second end;
• a second injection conduit having a first end and a second end;
• a fluid injecting means fluidly connected to the second ends of each of the first and second injection conduits so that the fluid injecting means can selectively inject fluids into the first and/or second injection conduits;
• a control unit for controlling the fluid injection means and the first and second selector valves;
• wherein the first injection conduit is fluidly connected, at its first end, to the first inlet/outlet conduit by a valveless junction, and the second injection conduits is fluidly connected, at its first end, to the first inlet/outlet conduit by a valveless junction,
• wherein the control unit is configured to consecutively,
• (i) open the first selector valve and close the second selector valve, and to then initiate the injecting means to inject a sample fluid which contains molecules to be sensed into the first injection conduit, so that the sample fluid flows through the first injection conduit and to the first selector valve without passing through the first flow cell conduit;
• and,
• (ii) close the first selector valve and open the second selector valve, and to then initiate the injecting means to inject a sample fluid, which contains molecules to be sensed, into the first injection conduit, so that the sample fluid flows through the first injection conduit and through the first flow cell conduit to the second selector valve,
• wherein the control unit is configured to carry out said steps of, (i) open the first selector valve and close the second selector valve, and to then initiate the injecting means to inject a sample fluid which contains molecules to be sensed into the first injection conduit, so that the sample fluid flows through the first injection conduit and to the first selector valve without passing through the first flow cell conduit, before carrying out the steps of, (ii) close the first selector valve and open the second selector valve, and to then initiate the injecting means to inject a sample fluid, which contains molecules to be sensed, into the first injection conduit, so that the sample fluid flows through the first injection conduit and through the first flow cell conduit to the second selector valve.

A method for performing biochemical sensing, using a flow conduit system which comprises

• a first flow cell conduit comprising one or more sensing areas for biochemical sensing;
• a first selector valve;
• a second selector valve which is fluidly connected to the first flow cell conduit;
• a first inlet/outlet conduit which has a first end which is connected to the first flow cell conduit and a second end which is connected to the first selector valve, so as to fluidly connect the first flow cell conduit to the first selector valve;
• a first injection conduit having a first end and a second end;
• a second injection conduit having a first end and a second end;
• a fluid injecting means fluidly connected to the second ends of each of the first and second injection conduits so that the fluid injecting means can selectively inject fluids into the first and/or second injection conduits;
• a control unit for controlling the fluid injection means and the first and second selector valves;
• wherein the first injection conduit is fluidly connected, at its first end, to the first inlet/outlet conduit by a valveless junction, and the second injection conduits is fluidly connected, at its first end, to the first inlet/outlet conduit by a valveless junction,
• wherein the control unit is configured to consecutively,
• (i) open the first selector valve and close the second selector valve, and to then initiate the injecting means to inject a sample fluid which contains molecules to be sensed into the first injection conduit, so that the sample fluid flows through the first injection conduit and to the first selector valve without passing through the first flow cell conduit;
• and,
• (ii) close the first selector valve and open the second selector valve, and to then initiate the injecting means to inject a sample fluid, which contains molecules to be sensed, into the first injection conduit, so that the sample fluid flows through the first injection conduit and through the first flow cell conduit to the second selector valve,
• wherein the control unit is configured to carry out said steps of, (i) open the first selector valve and close the second selector valve, and to then initiate the injecting means to inject a sample fluid which contains molecules to be sensed into the first injection conduit, so that the sample fluid flows through the first injection conduit and to the first selector valve without passing through the first flow cell conduit, before carrying out the steps of, (ii) close the first selector valve and open the second selector valve, and to then initiate the injecting means to inject a sample fluid, which contains molecules to be sensed, into the first injection conduit, so that the sample fluid flows through the first injection conduit and through the first flow cell conduit to the second selector valve;
• the method comprising the steps of,
• (a) filling the flow conduit system with buffer fluid;
• (b) opening the first selector valve, and closing the second selector valve;
• (c) using the injecting means to inject a sample fluid which contains molecules to be sensed, into the first injection conduit so that the sample fluid flows through the first injection conduit and to the first selector valve;
• (d) using the injection means to inject buffer fluid into the second injection conduit and flowing the buffer fluid along the second injection conduit, into the first inlet/outlet conduit, and through the first selector valve;
• (e) stopping the injection means from injecting the buffer fluid;
• (f) using said buffer fluid to restrict the flow of the sample fluid from the first injection conduit into the first inlet/outlet conduit;
• (g) closing the first selector valve and opening the second selector valve;
• (h) using the injection means to inject more sample fluid which contains molecules to be sensed, into the first injection conduit, so that the sample fluid flows through the first flow cell conduit;
• (i) using the first flow cell conduit to sense the amount of said molecules to be sensed which have bound to sensing areas of the first flow cell conduit.

A method for performing biochemical sensing, using a flow conduit system which comprises

• a first flow cell conduit comprising one or more sensing areas for biochemical sensing;
• a second flow cell conduit which comprises one or more sensing areas for biochemical sensing, which is fluidly connected to the first flow cell conduit;
• a first selector valve;
• a second selector valve which is fluidly connected to the first flow cell conduit;
• a first inlet/outlet conduit which has a first end which is connected to the first flow cell conduit and a second end which is connected to the first selector valve, so as to fluidly connect the first flow cell conduit to the first selector valve;
• a first injection conduit having a first end and a second end;
• a second injection conduit having a first end and a second end;
• a fluid injecting means fluidly connected to the second ends of each of the first and second injection conduits so that the fluid injecting means can selectively inject fluids into the first and/or second injection conduits;
• a control unit for controlling the fluid injection means and the first and second selector valves;
• wherein the first injection conduit is fluidly connected, at its first end, to the first inlet/outlet conduit by a valveless junction, and the second injection conduits is fluidly connected, at its first end, to the first inlet/outlet conduit by a valveless junction;
• a third injection conduit having a first end and a second end;
• a fourth injection conduit having a first end and a second end;
• and wherein the fluid injecting means is further fluidly connected to the second ends of each of the third and fourth injection conduits so that the fluid injecting means can selectively inject fluids into the third and/or fourth injection conduits, and
• wherein the third injection conduit is fluidly connected, at its first end, to the second inlet/outlet conduit by a valveless junction, and the fourth injection conduit is fluidly connected, at its first end, to the second inlet/outlet conduit by a valveless junction;
• wherein the control unit is configured to consecutively,
• (i) open the first selector valve and close the second selector valve, and to then initiate the injecting means to inject a sample fluid which contains molecules to be sensed into the first injection conduit, so that the sample fluid flows through the first injection conduit and to the first selector valve without passing through the first flow cell conduit;
• and,
• (ii) close the first selector valve and open the second selector valve, and to then initiate the injecting means to inject a sample fluid, which contains molecules to be sensed, into the first injection conduit, so that the sample fluid flows through the first injection conduit and through the first flow cell conduit to the second selector valve,
• wherein the control unit is configured to carry out said steps of, (i) open the first selector valve and close the second selector valve, and to then initiate the injecting means to inject a sample fluid which contains molecules to be sensed into the first injection conduit, so that the sample fluid flows through the first injection conduit and to the first selector valve without passing through the first flow cell conduit, before carrying out the steps of, (ii) close the first selector valve and open the second selector valve, and to then initiate the injecting means to inject a sample fluid, which contains molecules to be sensed, into the first injection conduit, so that the sample fluid flows through the first injection conduit and through the first flow cell conduit to the second selector valve;
• the method comprising the steps of,
• (a) filling the flow conduit system with buffer fluid;
• (b) opening the first selector valve;
• (c) using the injecting means to inject a sample fluid which contains molecules to be sensed, into the injection conduit whose first end is connected to the first inlet/outlet conduit by a first valveless junction which is located closest to the first flow cell conduit;
• (d) using said buffer fluid to restrict the flow of the sample fluid from the said injection conduit into the first inlet/outlet conduit;
• (e) using the injection means to inject buffer fluid into either the third or fourth injection conduit and flowing the buffer fluid along the second inlet/outlet conduit, through the second flow cell conduit, through the first flow cell conduit and through the selector valve;
• (f) stopping the injection means from injecting the buffer fluid;
• (g) closing the first selector valve;
• (h) using the injection means to inject more sample fluid which contains molecules to be sensed, into said injection conduit used in step (c) so that the sample fluid flows into the first flow cell conduit via the valveless junction which is located closest to the first flow cell conduit;
• (i) using the first flow cell conduit to sense the amount of said molecules to be sensed which have bound to sensing areas of the first flow cell conduit.