Profile: Chrono-log Corp. supplies medical products like platelet aggregometers and reagents. We introduced the model 700 whole blood/optical lumi-aggregometer available in a two or four channel configuration. This new aggregometer measures platelet function on patient samples, that use electrical impedance in whole blood or optical density in plasma with simultaneously measuring ATP release by the luminescence method. The model 700 aggregometer is also capable of performing the ristocetin cofactor assay for diagnosing patients with von willebrands disease.