Abstract: The present invention provides peptide-ligand conjugates containing a peptide, where a free form of the peptide is capable of displacing a second ligand specific for the peptide. The invention also provides a method of selecting a cell. The method includes the steps of contacting a cell population with a peptide-ligand conjugate, wherein the conjugate comprises a first ligand specific for a cell in the population conjugated to a peptide capable of displacing a second ligand specific for the peptide, thereby forming a cell-conjugate complex; contacting the peptide-ligand conjugate with the second ligand; and isolating the cell-conjugate complex. The method can further include the step of adding a free form of the peptide to release the cell from the complex. The invention additionally provides a method of diagnosing a condition using peptide-ligand conjugates.

Abstract: The present invention provides peptide-ligand conjugates containing a peptide, where a free form of the peptide is capable of displacing a second ligand specific for the peptide. The invention also provides a method of selecting a cell. The method includes the steps of contacting a cell population with a peptide-ligand conjugate, wherein the conjugate comprises a first ligand specific for a cell in the population conjugated to a peptide capable of displacing a second ligand specific for the peptide, thereby forming a cell-conjugate complex; contacting the peptide-ligand conjugate with the second ligand; and isolating the cell-conjugate complex. The method can further include the step of adding a free form of the peptide to release the cell from the complex. The invention also provides a subpopulation of cells containing two or more specifically isolated cells and methods of isolating cell subpopulations. The invention additionally provides a method of diagnosing a condition using peptide-ligand conjugates.

Abstract: The invention provides a nonenzymic method for the release of cells which have been selected from a heterogeneous cell suspension by antibody-mediated binding to beads or other solid support. The method entails forming within the cell suspension a complex comprising the solid support linked to a primary monoclonal antibody, which in turn is bound to a cell surface antigen on the target cells. The complex is separated from the cell suspension, and then contacted with a specific peptide which binds to the primary antibody, displacing the antibody from the cell surface antigen, thereby releasing the target cell from the complex. The invention also provides methods for positive/negative cell selection wherein target cells having a first antigen are selected from a heterogeneous cell suspension containing undesired cells having a second antigen.

Abstract: The invention provides a non-enzymatic method for the release of cells which have been positively selected from a heterogeneous cell suspension by antibody-mediated binding to beads or other solid support. The method entails forming within the cell suspension a complex comprising the solid support linked to a primary antibody, which in turn is specifically bound to a cell surface antigen on the target cells. The complex is separated from the cell suspension, and then contacted with a specific peptide which binds to the primary antibody, displacing the antibody from the cell surface antigen, thereby releasing the target cell from the complex. The invention also provides methods for positive/negative cell selection wherein target cells having a first antigen are selected from a heterogeneous cell suspension containing undesired cells having a second antigen.