Abstract: The invention relates, firstly, to a biomolecule-releasing cell characterised by a surface protein with an extracellularly exposed ligation peptide sequence for enzymatic conjugation of an adapter ligand, said adapter ligand being suitable for the indirect or direct coupling of a molecular catcher structure which has at least one specific binding site for the released biomolecules and which is at a distance from the specific binding site, secondly, to a method for selecting such a cell, and thirdly, to a means for this method comprising the surface protein that is characterised by an extracellularly exposable ligation peptide sequence for enzymatic conjugation of an adapter ligand, a nucleic acid coding for the surface protein, an expression vector for the nucleic acid, and a cell containing the expression vector.

Abstract: The invention relates, firstly, to a biomolecule-releasing cell characterised by a surface protein with an extracellularly exposed ligation peptide sequence for enzymatic conjugation of an adapter ligand, said adapter ligand being suitable for the indirect or direct coupling of a molecular catcher structure which has at least one specific binding site for the released biomolecules and which is at a distance from the specific binding site, secondly, to a method for selecting such a cell, and thirdly, to a means for this method comprising the surface protein that is characterised by an extracellularly exposable ligation peptide sequence for enzymatic conjugation of an adapter ligand, a nucleic acid coding for the surface protein, an expression vector for the nucleic acid, and a cell containing the expression vector.

Abstract: A method for performing homogeneous immunoassay formats with electrochemical detection in solution includes combining two different conjugates as reagents with a sample or a sample/buffer mixture, one conjugate including a redox marker and an analyte molecule and the second conjugate including an anti-redox marker antibody or a specifically binding fragment thereof and a molecule specifically binding the analyte.

Abstract: A method for performing homogeneous immunoassay formats with electrochemical detection in solution includes combining two different conjugates as reagents with a sample or a sample/buffer mixture, one conjugate including a redox marker and an analyte molecule and the second conjugate including an anti-redox marker antibody or a specifically binding fragment thereof and a molecule specifically binding the analyte.