Micro-fluidic devices for assaying biological activity

A process of assaying biological activity in a micro-fluidic device, wherein said biological activity comprises production of a biological material of interest, said process comprising:

• culturing one or more biological cells in a first holding pen of said micro-fluidic device, wherein said one or more cells produce said biological material of interest, wherein said micro-fluidic device comprises a housing, and wherein said housing comprises:
• a base;
• a micro-fluidic structure disposed on said base;
• said first holding pen;
• and
• a second holding pen adjacent to said first holding pen;
• wherein said micro-fluidic structure and said base define a flow region in which said first and second holding pens are disposed, and
• wherein said first holding pen comprises an isolation region having a single opening, and a connection region, said connection region having a proximal opening to said flow region and a distal opening to said isolation region, and wherein said isolation region of said first holding pen is an unswept region of said micro-fluidic device;
• introducing one or more capture micro-objects into said first holding pen, wherein each said capture object comprises a binding substance that specifically binds said biological material of interest;
• allowing said biological material of interest produced by said one or more biological cells to bind to said one or more capture micro-objects in said first holding pen;
• moving said one or more capture micro-objects comprising said bound biological material of interest to said second holding pen;
• and
• assessing said bound biological material of interest in said second holding pen.