Provided are methods and kits for activating T cells, the method comprising providing a population of T cells, adding a plurality of first agents, where the first agent comprises a T-cell activator and a first binder moiety, and adding a second agent comprising a plurality of capture oligomers, where at least a segment of at least one of the plurality of capture oligomers is capable of associating with the first binder moiety. The method further comprises incubating the population of T cells, whereby at least a portion of the population of T cells is activated.