TREM-like transcript-1 (TLT-1) was initially characterized as the putative inhibitory receptor within the TREM locus on chromosome 6 and was suggested to play a critical role in modulating TREM-associated immunity. Recently, TLT-1 was found not to function as an inhibiting member of the TREM family; however, it may play a significant role in maintaining vascular hemostasis, coagulation, and inflammation at sites of injury through its location in platelets. In this study, we have successfully generated a monoclonal antibody that can be applied to assays, including enzyme-linked immunosorbent assay (ELISA), Western immunoblotting, immunofluorescence, and Fluorescence-Activated Cell Sorter (Becton-Dickinson) (FACS), for the study of TLT-1 functions in physiological and pathological conditions.