Abstract: A method for determining platelet activation by utilizing numeric counts of platelets before a sample of platelets has been activated and after the activatable platelets are activated with a platelet activation agonist and using the difference between such counts as an indication of the platelet activity of the sample. There is also disclosed a method for using the electronic impedance cell counting technique for determining platelet activation wherein EDTA is used as a preservative by counting the platelets in an EDTA preserved sample using an electronic impedance cell counting technique and subtracting from that number the number of platelets remaining after the activatable platelets in a second sample have been activated with a platelet agonist in the absence of EDTA and using that difference as a measure of platelet activity.

Abstract: The present invention is directed to a method and apparatus for detection of a diagnostically significant amount of clot in an aliquot of blood. In a preferred embodiment, the method uses a cocktail of activators to facilitate and proctor absolute activation of Factor XII (the contact factor for the intrinsic pathway of coagulation). Possible activators include Celite®, kaolin, glass beads, colloidal silica, and diatomaceous material. This cocktail formulation is important because some individuals respond differently to different activators and hence, the cocktail formulation facilitates standardization of the patient population by reducing the patient-activator sensitivity artifacts.

Abstract: A method for determining platelet activation by utilizing numeric counts of platelets before a sample of platelets has been activated and after the activatable platelets are activated with a platelet activation agonist and using the difference between such counts as an indication of the platelet activity of the sample. There is also disclosed a method for using the electronic impedance cell counting technique for determining platelet activation wherein EDTA is used as a preservative by counting the platelets in an EDTA preserved sample using an electronic impedance cell counting technique and subtracting from that number the number of platelets remaining after the activatable platelets in a second sample have been activated with a platelet agonist in the absence of EDTA and using that difference as a measure of platelet activity.

Abstract: A method for determining platelet activation by utilizing numeric counts of platelets before a sample of platelets has been activated and after the activatable platelets are activated with a platelet activation agonist and using the difference between such counts as an, indication of the platelet activity of the sample. There is also disclosed a method for using the electronic impedance cell counting technique for determining platelet activation wherein EDTA is used as a preservative by counting the platelets in an EDTA preserved sample using an electronic impedance cell counting technique and subtracting from that number the number of platelets remaining after the activatable platelets in a second sample have been activated with a platelet agonist in the absence of EDTA and using that difference as a measure of platelet activity.

Abstract: The present invention utilizes a novel reaction chamber. The reaction chamber is made from a pierceable self-sealing material which may be in the form of a long, narrow tube. The may contains a single reagent within the entire length of the tube or the tube may be segmented into a plurality of distinct chambers. Numerous tests can be performed within a given tube, separated either by distance or a physical barrier, with no degradation or interference between the testing sites. The test results may be conveniently determined using any of the known detection methodologies, including photometric, electromechanical, spectrophotometric, and nephlometric detection mechanisms.