Provided herein are cell surface conjugates containing a cell surface molecule and at least one agent, such as at least one affinity tag, and engineered cells expressing such cell surface conjugates.In some embodiments, the cell surface molecule does not contain an intracellular signaling domain or is not capable of mediating intracellular signaling. In some embodiments, the cells engineered to contain the cell surface conjugate, such as T cells, further contain a genetically engineered recombinant receptor that specifically binds to antigens, such as a chimeric antigen receptor (CAR). Also provided are methods of detecting, identifying, selecting or targeting cells expressing the cell surface conjugtes, such as in connection with methods of manufacturing engineered cells or in connectionwith administration of such cells to subjects, including methods of adoptive cell therapy.