A custom MatLab program was then used to quantify the fluorescence level of each band in both the calibration curve samples and in the 1X and 3X sample lanes. The extracted EPI internal standard value was quantified from the 3X patient plasma sample and compared to the standard curve. Since EPI was spiked in at a known amount, the difference between the expected and observed EPI concentrations indicated loss resulting from the extraction process. This difference was used to scale the DOX and DOL values to account for loss through the extraction process. The intensity values determined for the DOX and DOL bands in the 3X sample lane were compared to the DOX and DOL calibration curve to determine concentration.