Abstract: A method is disclosed for identifying a member of a peptide library that interacts with a target molecule in situ, the method including expressing immobilised nucleic acid molecules to produce the peptide library in a way that each member of the peptide library is immobilised on the nucleic acid molecule from which it was expressed; contacting the immobilised peptide library with the target molecule; and detecting an interaction between at least one member of the peptide library and the target molecule. The method further comprises sequencing the plurality of nucleic acid molecules in situ on the solid support, such that the at least one member of the peptide library that interacts with the target molecule can be immediately identified, at least by the sequence of the nucleic acid molecule from which it was expressed, without requiring additional or secondary analysis or characterising procedures in order to identify the useful members of the library.

Abstract: A method is selects membrane-translocating peptides (MTPs) from a peptide display library that are capable of crossing or penetrating a lipid membrane. A plurality of nucleic acid constructs that encode displayed peptides are expressed, resulting in the formation of a plurality of nucleic acid-peptide complexes, each complex comprising at least one displayed peptide associated with the corresponding nucleic acid construct encoding the displayed peptide; the complexes are exposed to a population of membrane-encapsulated compartments, allowing a translocating reaction to occur; complexes that remain unassociated with the membrane are removed; optionally complexes that are associated with the membrane are removed; and internalized nucleic acid-peptide complexes are recovered. The membrane-encapsulated compartments may be artificial vesicles such as liposomes, or populations of one or more cell types.

Abstract: A method is provided for selecting membrane-translocating peptides (MTPs) from a peptide display library that are capable of crossing or penetrating a lipid membrane. A plurality of nucleic acid constructs that encode displayed peptides are expressed, resulting in the formation of a plurality of nucleic acid-peptide complexes, each complex comprising at least one displayed peptide associated with the corresponding nucleic acid construct encoding the displayed peptide; the complexes are exposed to a population of membrane-encapsulated compartments, allowing a translocating reaction to occur; complexes that remain unassociated with the membrane are removed; optionally complexes that are associated with the membrane are removed; and internalised nucleic acid-peptide complexes are recovered. The membrane-encapsulated compartments may be artificial vesicles such as liposomes, or populations of one or more cell types.