Document ID: DQ175 Relevant to following products: WorkOut 2.0 Manta Document description: Application Example: Cortisol Assay
A cortisol assay requires counting of absorbance at 405nm with a second reading at 495nm The wells are all in duplicates, there are an NSB (Blank), seven standards including a zero standard, two control, and the remainder unknown. The 495nm read is subtracted from the 405nm read. The difference is blank corrected and the result is plotted using 4 PL concentration vs. B/B0.
To set this up in WorkOut 1.5: Setup the measurements, difference and blank correction using the default transforms. To setup the B/B0 analysis create a User Defined Transform (select to use Auto-mean). When the Transform Expression editor is displayed use the controls to enter your B/B0 expression: to do this select which wells you want to store the expression (typically all of your wells), then use the x’= control to enter the expression and press return for it to be entered into all of the selected wells. Depending on the standards are setup your B/B0 will be calculated something like:
100 * ((x-standard1)/(standard7 – standard1))
(Assuming standard7 is B0 and standard1 B)
WorkOut replaces the x with the well that the expression is in.
After you have setup this transform add the Standard Curve fit using the B/B0 output as its input.