I need to calculate the molar extinction coefficient for phycocyanin.

Question

I have a calibration curve, with the equation of the line, and the concentrations of the plotted points, with absorbency plotted against concentration (mg/ml) How do I solve using the Beer Lambert equation. 

Answer 1

The extinction coefficient is usually in M-1cm-1 so using molar mass of phycocyanin convert mg/ml to M and then from the calibration curve equation, which should be in the form of a straight line (y=mx+b), substitute 1 M for x and solve for y. That should give you the extinction coefficient.