Question

RNA (μg)	Absorbance at 260 nm
0.00	0.208
10.01	0.545
20.02	0.733
30.03	1.099
40.04	1.327

The data in the table are used to create 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 ?y-intercept of the best straight line fit to the calibration curve. Do not subtract the blank reading when creating the calibration curve.

m=

μg−1

b=

Using the slope and intercept of the calibration curve, determine the quantity of RNA in a sample that gives an absorbance of 0.6740.674.

mass =

?g

μg−1

b=

Using the slope and intercept of the calibration curve, determine the quantity of RNA in a sample that gives an absorbance of 0.6740.674.

mass =

?g

Answer 1

From the plot y= 0.0279x + 0.224.

Upon comparing it with linear line equation.

m = 0.0279

b = 0.224.

Slope = 0.0279

intercept = 0.224

y= absorbance

x = RNA concentration in ug.

For the unknown, y = 0.674.

Putting the value of y in the equation we will get

0.674 = 0.0279x+ 0.224

0.674 - 0.224 = 0.0279x.

0.45 = 0.0279x

x = 45/0.0279

=16.12ug.

So, the concentration of unknown is 16.12ug.

Please write to me if you need more help.