Fluid handling methods for use in mesoscale analytical devices

A method for detecting an analyte in a fluid, cell-containing sample, the method comprising the steps of:

• (i) providing a device comprising:
• a solid substrate microfabricated to define:
• a sample inlet port;
• and
• a mesoscale flow system comprising:
• a sample flow channel extending from said inlet port;
• and
• a cell handling region for treating cells disposed in fluid communication with said flow channel, said cell handling region comprising a cell lysing structure;
• and
• means for detecting an analyte in a fluid sample in said flow system;
• (ii) delivering a cell-containing fluid sample to the inlet port and through the flow system to the cell lysing structure in the cell handling region thereby to lyse cells in the sample producing a lysed cell sample;
• and
• (iii) detecting an analyte in the fluid sample in the flow system with the detection means.

A method for analyzing a fluid, cell-containing sample, the method comprising:

• (i) providing a device comprising:
• a solid substrate microfabricated to define:
• a sample inlet port;
• and
• a mesoscale flow system comprising:
• a sample flow channel extending from said inlet port;
• and
• a cell handling region for treating cells disposed in fluid communication with said flow channel, said cell handling region comprising a cell capture region comprising immobilized binding sites which reversibly bind a preselected cell surface molecule of a cell population in a cell-containing fluid sample;
• and
• means for inducing flow of cells in said sample through said mesoscale flow channel and said cell handling region;
• and
• means for detecting an analyte in a fluid sample in said flow system;
• (ii) delivering a fluid, cell containing sample to the inlet port;
• (iii) inducing flow of the cell-containing sample through the flow system within the flow inducing means:
• at a first flow rate sufficiently slow to permit capture of cells in a cell population in the sample by the binding sites, thereby to separate the cell population from the sample;
• and
• at a second flow rate, higher than the first flow rate, and sufficient to release the separated cells from the capture region;
• and
• (iv) detecting an analyte in the fluid sample in the flow system with the detection means.

A method for analyzing a fluid, cell-containing sample, the method comprising:

• (i) providing a device comprising:
• a solid substrate microfabricated to define:
• a sample inlet port;
• and
• a mesoscale flow system comprising:
• a sample flow channel extending from said inlet port;
• and
• a cell handling structure for treating cells disposed in fluid communication with said flow channel, said cell handling structure defining:
• a cell sieve comprising means defining a plurality of flow passages of restricted size allowing only cells of a sufficiently small diameter to pass therethrough;
• and
• a cell lysing structure;
• means for inducing flow of cells in a sample through said mesoscale flow channel and said cell handling structure;
• and
• means for detecting an analyte in a fluid sample in said flow system;
• (ii) delivering a fluid, cell-containing sample to the inlet port through the flow system with the flow inducing means to the cell handling structure, to permit cell sorting of the sample in the cell sieve, and cell lysis of the cell sample in the cell lysing structure;
• and
• (iii) detecting an analyte in the sample in the flow system with the detection means.

A method for analyzing a cell-containing fluid sample, the method comprising:

• (i) providing a device comprising:
• a solid substrate microfabricated to define:
• a mesoscale cell handling structure;
• and
• at least two mesoscale flow systems, each of which comprise a flow channel and an analyte detection region, one of said flow systems being adapted to analyze a sample, the other being adapted as a control, and said flow systems being in fluid communication with said cell handling structure;
• and
• means for inducing flow of a sample through said cell handling structure and then through both said flow systems, thereby to permit comparison of data from the detection regions of said systems;
• (ii) delivering a cell-containing fluid sample to said inlet port, and through the cell handling structure and the mesoscale flow systems with the flow inducing means;
• and
• (iii) detecting and comparing data from the detection regions of said flow systems.