Graphpad

BMS1023 GraphPad Practical (Autumn semester 2015)

Dr Alfred Thumser & Dr Ian Bailey

Learning Objectives:

* Entering the data

* Plotting the data: Line graphs (XY plots)

* Analysis of the data: Linear regression

* Plotting the data: Column plots

* Analysis of the data: t-test

It is recommended that you use GraphPad Prism software for your data analysis. GraphPad Prism software can be downloaded through the University of Surrey Application JukeBox (https://software.surrey.ac.uk/jukeboxdrm/do/manageStreamit?method=show).

A. Perform a linear regression on the data provided: [100]

1. The Instructions for entering data can be found on SurreyLearn.

2. Enter the data values that you obtained for the standard curve in the protein Assay practical.

3. Perform a linear regression analysis. Provide a short explanation of what you did (5 lines maximum) [15].

The linear regression analysis was completed by firstly selecting the ‘=Analyze’ button on the top menu bar. Once the ‘Analyze Data’ box showed, I then selected the ‘Linear regression’ option. Once selecting ‘Ok’, I then set the parameters. I selected a ‘Residual plot’ and ticked the box to force the line of best fit to go through the X-axis at 0.0 and also set it to go through the Y-axis at 0.0. I made sure that the ‘Test departure from linearity with runs test’ box was also selected. I set the range to ‘Auto’. After clicking on ‘Okay’, I had successfully completed the linear regression analysis.

4. Plot a XY Graph, including appropriate titles, and insert below [30]:

5. What was your R2 value? [5]

0.9865

6. Insert your values for the slope (m) and Y-axis intercept (c) [10]

Slope: 0.07393 ± 0.002497

After interpolation: 0.07393 (Best-fit values)

0.06849 to 0.07937 (95% confidence intervals)

Y-axis intercept: 0.005437 ± 0.007014

After interpolation: 0.005437 (Best-fit values)

-0.009845 to 0.02072 (95% confidence intervals)...