Question

The data in the table at the right show a calibration curve for the determination of RNA from its absorbance at 260 nm. Use a spreadsheet and the least-squares method to determine the slope and intercept of the best straight line fit to the calibration curve. (Do not subtract the blank reading when creating your calibration curve.)

RNA /absorbance at 260nm

0.00 /.243

10.09/.460

20.18/.788

30.27/1.072

40.36/1.303

find slope in abs/ug and intercept

Using the slope and intercept of the calibration curve, determine the quantity of RNA in a sample that gives an absorbance of 0.623. find mass RNA in ug

Answer 1

Please find the attached graph with R2=0.997

From the graph Slope=0.027 abs/ug and intercepet=0.2268.

Given unknown absorbance=0.623

Substituting this absorbance value in the eqution A=intercept+Slope x concentration (Y=a+bx)

0.623=0.2268+0.027 x concentration

Unknown Concentration of RNA=(0.623-0.2268)/0.027 abs/ug=14.67 ug

Therefore mass of RNA=14.67 ug.