Table 1. PCa serum t-PSA measurement comparison.

PCa Serum Samples	Pathologic Tumor Stage of PCa Serum Donor	Measured Absorbance of t-PSA	Coefficient of Variation	t-PSA (ng/mL) Measurement Comparison Using Linear Regression Equations from R&D Immunoassay PSA Calibrant and CS
				R&D rPSA Calibrant	Calbiochem PSA CS	Scripps PSA CS
1	2c	0.80	9.6	4.0	17.4	6.5
2	3b	0.60	1.7	38.9	133.5	54.0

The t-PSA serum levels of two PCa samples examined in the R&D ELISA were computed using the linear regression equations from the R&D ELISA rPSA calibrant and R&D tested PSA CS.