Cellular High Throughput Encapsulation for Screening or Selection

A method for selecting a sequence set from a library of expressed nucleic acid sequences, wherein

• a plurality of cells is provided, each cell comprising an expressed nucleic acid sequence expressed as a target protein in said cell,
• said plurality of cells is encapsulated in an encapsulating step, comprising
• treating said plurality of cells with a cationic polysaccharide in a cationic treatment step,
• treating said plurality of cells with an anionic polysaccharide in an anionic treatment step,
• said encapsulating step giving rise to a plurality of encapsulated cells,
• solubilizing the membrane of said encapsulated cells in a solubilization step, giving rise to a plurality of solubilized compartments,
• contacting said plurality of solubilized compartments, in a labelling step, with
• a ligand to said target protein, said ligand bearing a detectable label, or with
• an indicator of an enzymatic activity of said target protein, said enzymatic activity converting said indicator to a detectable label,
• selecting a subset of said plurality of solubilized compartments as a function of detectable label present in said solubilized compartments in a selection step, giving rise to a selection, and
• isolating said expressed nucleic acid sequences from the selection as a selected sequence set in an isolation step.