Question

How do I get the average of dopachrome and STDEV of Dopachrome when I add 2.0 ml DOPA in the tube?

Testing Reaction Sets 1. Zero the spec at 475 and blank it using the appropriate blank for the first reaction set of tubes (1-1, 1-2 & 1-3). Remove the blank. 2. You will stagger the start and measurements of your three reaction tubes by 15 seconds. The reaction starts when you add the DOPA, so add it only to the tubes you are about to measure when you are ready to start: Start reaction tube 1-1 of the first reaction set by adding 2.0mL of DOPA, cap and invert to mix, wipe the tube and start the timer. Immediately record into the table the absorbance at 475 and repeat this for tube 1-2. It should be 15 seconds after you started tube 1. Repeat this for tube 1-3, which would be 30 seconds after the timer was started for tube 1. Continue to record absorbance values for tubes 1-1, 1-2 and 1-3 every minute for 10 minutes. 3. When you have finished the first set of reaction measurements, repeat the procedure for the second set of enzyme reaction tubes (2-1, 2-2 & 2-3). Remember to blank with the appropriate blank before starting the second set of reactions. Table 3 Russet Potato 1 0.2mL Reaction 1 0.2mL Reaction 2 0.2mL Reaction 3 Absorbance OD475 Average of Reactions Average Absorbance OD475 Time Absorbance OD475 Absorbance OD475 Average mM Dopachrome (minutes) 0 2 5 6 7 8 9 10

Answer 1

To find the average of Dopachrome, you need to plot and correlate the absorbance of the product released with the standard curve of the product which is in the form of y=mx+c . From the graph itself you can check the concentration of dopachrome fro each absorbance values and then calculate the average concentration from the 3 values of aborbance plotted against the graph.

For the standard deviation case, you can subtract the average value of the dopachrome from individual values of the concentration of dopachrome which is 2ml . Then follow the simple formula of standard deviation .

Or you can use Minitab as your statistical help and copy paste the Average values in one column and the initial concentration of the enzyme in one and directly select the option of Standard deviation and let the software calculate it.