Abstract: Disclosed herein are methods for performing assays, including general functional assays, on a biological cell. Also disclosed herein are methods of barcoding the 5? ends of RNA from a biological cell and methods of preparation of expression constructs from the barcoded RNA. The barcoded RNA can encode proteins of interest, such as B cell receptor (BCR) heavy and light chain sequences. The expression constructs can be generated individually or in a paired/multiplexed manner, allowing rapid re-expression of individual proteins or protein complexes.

Abstract: Systems for operating a microfluidic device are described. The systems comprise a first surface configured to interface and operatively couple with a microfluidic device and a lid configured to retain the microfluidic device on the first surface. The lid comprises a first portion having a first fluid port configured to operatively couple with and flow fluidic medium into and/or out of a first fluid inlet/outlet of the microfluidic device and a second portion having a second fluid port configured to operatively couple with and flow fluidic medium into and/or out of a second fluid inlet/outlet of the microfluidic device. The second portion of the lid is separable from the first portion and movable between a closed position in which the second fluid port of the second portion of the cover is operatively coupled with the second fluid inlet/outlet of the microfluidic device and an open position in which a portion of the microfluidic device that contains the second fluid inlet/outlet is exposed.