This is a study to determine 1) the consistency of platelet-rich plasma produced by several methods, and 2) whether the platelet content of platelet-rich plasma can be accurately estimated from a baseline CBC platelet count.

In the first phase of this study a baseline CBC platelet count will be performed on each subject and then platelet-rich plasma (PRP) prepared from the same blood sample by six different methods. The platelet count will be measured in each PRP preparation and compared to the CBC platelet count to determine the platelet yield for each method.

In the second phase of the study a baseline CBC platelet count will be performed on each subject and then platelet-rich plasma (PRP) prepared from the same blood sample by six different methods. The CBC platelet count will be used to calculate the estimated platelet content of each sample/method based on the platelet yields determined in the first phase. The platelet count will be measured in each PRP preparation and compared to the estimated platelet content to determine the predictive accuracy for each method.

Inclusion Criteria:

• English speaking

Exclusion Criteria:

• platelet count < 150,000
• platelet count > 350,000
• History of blood disorder
• History of altered platelet function
• History of chemotherapy or radiation therapy

normal adults