Methods for isolating target cells from blood

A method for isolating target cells from whole blood, comprising:

• (a) mixing in an open container
• (i) an undiluted whole blood sample having a volume of between 1 ml and 7.5 ml, and
• (ii) binding agents, wherein each binding agent comprises (A) a primary binding agent comprising an antibody capable of binding to at least one cellular epitope on target cells in the undiluted whole blood sample, and (B) a first linker bound to the primary binding agent, wherein the first linker comprises a biotin linker,
• wherein the mixing occurs for a time and under conditions suitable to promote binding of the primary binding agents to the target cells to generate binding agent-attached target cells in the undiluted whole blood sample;
• (b) contacting the binding agent-attached target cells in the undiluted whole blood sample contained in the open container with a plurality of buoyant reagents, wherein each buoyant reagent comprises a second linker bound to the buoyant reagent, wherein the second linker comprises streptavidin, wherein the contacting occurs for a time and under conditions suitable to promote binding of the second linker to the first linker to generate an undiluted buoyant reagent-attached target cell mixture;
• (c) diluting the undiluted buoyant reagent-attached target cell mixture contained in the open container by at least 20% to produce a diluted buoyant reagent-attached target cell mixture;
• (d) applying a vectorial force to the diluted buoyant reagent-attached target cell mixture to generate a stratified diluted buoyant reagent-attached target cell mixture;
• (e) removing the buoyant reagent-attached target cells from the stratified diluted buoyant reagent-attached target cell mixture;
• and
• isolating the target cells from the buoyant reagent-attached target cells;
• wherein the target cells are not platelets or red blood cells.