Methods of assaying micro-objects in a microfluidic device

(canceled)

-6. (canceled)

-16. (canceled)

The method of 13, wherein the prepolymer composition comprises:

• a first polyethylene glycol polymer molecule and a second polyethylene glycol polymer molecule, each comprising a respective polyethylene glycol moiety and a covalently linked reactive moiety Rx;
• a crosslinker molecule comprising a first reactive moiety RxP disposed at a first end of a linker moiety L and a second reactive moiety RxP disposed at a second end of the linker moiety L, wherein each of the first and the second crosslinker moiety RxP is configured to be activatable to react with a respective reactive moiety Rx of the first and the second polyethylene polymer molecules.

-24. (canceled)

(canceled)

(canceled)

-38. (canceled)

A microfluidic device comprising:

• a microfluidic circuit material defining a flow region;
• a chamber comprising a proximal opening fluidically connecting the chamber to the flow region;
• wherein a micro-object is introduced into the flow region of the microfluidic device allowing a reagent to diffuse from the chamber to the flow region and to contact the micro-object.