Methods for isolating pancreatic islets

A method of operating microfluidic device to separate acinar cells from islet cells, the method comprising:

• providing a sample stream into a combining passage from an upstream sampling passage including cellular aggregates including acinar cells and islet cells;
• providing a focusing stream from an upstream focusing passage to the combining passage to, together with the sample stream, form a combined stream, the focusing stream directing the sample stream toward a bifurcating passage that defines a bifurcating flow resistance and that defines a passage width and depth;
• discharging a first portion of the combined stream through the bifurcating passage;
• discharging a second portion of the combined stream through a main discharge, the main discharge including a main discharge resistance;
• and
• varying the main discharge resistance using a main discharge multiplexer to establish a threshold occlusion level below which causes cells of the of the combined stream to deform and enter the bifurcating passage.

A method of operating microfluidic device to separate acinar cells from islet cells, the method comprising:

• providing a sample stream including islet cells and acinar cells from an upstream sampling passage into a combining passage;
• providing a focusing stream from an upstream focusing passage to the combining passage to, together with the sample stream, form a combined stream, the focusing stream directing the islet cells and acinar cells toward a bifurcating passage that defines a bifurcating flow resistance and that defines a passage width and depth;
• discharging a first portion of the combined stream including the islet cells through a main discharge, the main discharge including a main discharge resistance;
• and
• varying the main discharge resistance using a main discharge multiplexer to cause acinar cells of the of the combined stream to deform and enter the bifurcating passage.