Salivary blood is known to increase in patients with intraoral mucosal bleeding. Mucosal bleeding is a frequent sequelae of thrombocytopenia, which is typically managed with platelet transfusion. Within the past few years, multiple different types of platelet products have become available, each with potential differences in efficacy. Typically, platelet transfusion efficacy is demonstrated by the increase in platelet count after transfusion. However this approach is complicated by the fact that activated platelets tend to produce lower post-transfusion platelet counts, but may be more efficacious in a bleeding patient. Intraoral blood levels, measured by salivary transferrin, urine dipstick hemoglobin or another method, could be used as an in vivo assay to monitor a patient's response to platelet transfusion and compare different types of platelet products.