Dear Jay, I think you got me a bit wrong. This was not an attempt to subverse the presentation of measured data by using "politically incorrect" methods. As those colorimetric assays usually are not supposed to be a thesis of itself, one usually is interested in quick and accurate results (actually, protein determinations are quite annoying to me). Spreadsheets like excel provide some quick and easy means to reach that goal and it's easy to set up forms where you just enter your data and you get the results you need for your actual experiment.
Drawing a regression curve allows to display the corresponding function. Regardless if you want linear or polynomic regression, if you plot the diagram in the canonical way (y-axis: OD, x-axis: concentration), you will have to do additional mathematics to obtain an equation that allows you to calculate concentrations from ODs. When you do it as I suggested (x: OD, y: conc), excel will give you directly an equation you may use immediately for downstream calculations (just copy the coefficients into the spreadsheet). You simply don't need to calculate the inverse function by yourself which costs time and may introduce errors in such a routine task (and might become quite difficult if the regression is not linear). Of course, one should understand what one is doing and not just enter some figures into a spreadsheet you snatched from your (colleague who snatched it from his)^n. Or your PI told you to enter the data into that form and you actually have no idea what's happening. I also would not blame Sudheer for asking his question. It shows there might be some profound deficits in the concurrent education of students and young scientists. Probably the focus gets more and more on reproducing knowledge and being fast (in order to get good gradations, scholarships, grants, good jobs, etc etc) instead of understanding what really happens and being able to dissect and analyze problems and to get your feet on the ground in unknown terrain. Wo _______________________________________________ Methods mailing list [email protected] http://www.bio.net/biomail/listinfo/methods
