In-line pressure accumulator and flow-control system for biological or chemical assays

A method of delivering a reagent to a flow cell, the method comprising:

• fluidly coupling a flow cell to a loading zone of a flow-control system, the flow-control system, comprising:
• a reagent reservoir that stores a reagent,
• a pressure accumulator that is fluidly coupled to the reagent reservoir and the loading zone through a first valve configured to be selectively positioned in a first valve open state and a first valve closed state,
• the loading zone is fluidly coupled to the pressure accumulator through a second valve configured to be selectively positioned in a second valve open state and a second valve closed state, and
• a system pump that is fluidly coupled to the loading zone and positioned downstream from the loading zone;
• flowing the reagent from the loading zone into the pressure accumulator by positioning the first valve in the first valve closed state and the second valve in the second valve open state and by increasing an operating volume of the pressure accumulator.

A method of delivering a plurality of reagents to a flow cell, the method comprising:

• fluidly coupling a flow cell to a loading zone of a flow-control system, the flow-control system, comprising:
• a plurality of reagent reservoirs, each of the plurality of reagent reservoirs storing one of the reagents,
• a plurality of pressure accumulators, each of the plurality of pressure accumulators fluidly coupled to one of the reagent reservoirs and the loading zone,
• a plurality of first valves, each of the plurality of first valves between one of the reagent reservoirs and one of the pressure accumulators, each of the plurality of first valves configured to be selectively positioned in a first valve open state and a first valve closed state,
• the loading zone is fluidly coupled to the pressure accumulators, and
• a system pump that is fluidly coupled to the loading zone and positioned downstream from the loading zone,
• flowing a selected reagent from one of the reagent reservoirs into one of the pressure accumulators by positioning one of the first valves in the first valve opened state;
• and
• flowing the selected reagent from the one of the pressure accumulators into the loading zone by positioning the one of first valves in the first valve closed state and by reducing an operating volume of the one of the pressure accumulators.