ORLISTAT PRACTICAL WRITE-UP INSTRUCTIONS
In this practical write up, you will be required to produce some graphs and answer some questions on the practical you carried out with the drug “Orlistat”.
- Calculate Orlistat final concentration and fill in data table
Complete the table below filling in the final concentrations of Orlistat and final absorbance value (A1 – A2).
(4 marks)
| Tube no. | Orlistat final concentration (µM) | Absorbance at 410 nm (A1) | Absorbance at 500 nm (A2) | Absorbance A1 – A2 = A3 |
| 1 | ||||
| 2 | ||||
| 3 | ||||
| 4 | ||||
| 5 | ||||
| 6 | ||||
| 7 |
- Plot the graphs
Now, you will need to plot two graphs from this data. YOU MUST TITLE AND LABEL THE GRAPHS APPROPRIATELY.
Graph 1. Plot a concentration-response curve of your data (i.e. Orlistat concentration versus Absorbance A3). You may use a graphics package (e.g. Excel), or, if you prefer, you may draw the graph by hand.
(10 marks)
Graph 2. You have been provided with some semi-log graph paper; plot the concentration-response curve for your data on this semi log graph paper.
(10 marks)
- Estimate Orlistat IC50 value
From the concentration-response graph on semi-log scale, you will need to estimate the IC50 value for Orlistat. YOU MUST SHOW EVIDENCE OF HOW YOU REACHED THIS VALUE ON YOUR GRAPH (i.e. indicate how you read the IC50 value off the graph.
(5 marks)
- Refer to the literature for other Orlistat IC50 values
Now you need to compare your Orlistat IC50 value with other, published data on Orlistat. Find references using www.pubmed.com and comment on the estimated IC50 value of Orlistat obtained in your experiment with the literature values (i.e. is it similar or different?).
Note: make sure the article you reference actually used pancreatic lipase in the experiments and make sure you quote the IC50 value of Orlistat from that article and not any other pancreatic lipase inhibitor that may have been investigated.
Ensure that you provide a reference AND MAKE SURE THAT YOU REFERENCE THE ARTICLE CORRECTLY, i.e. in the Harvard style of referencing. If you do not know what this is – look it up!
(6 marks)
TOTAL MARKS: 35
