DO YOU INCLUDE ANOMOLIES IN A GRAPH?
((IVE CONSTRUCTED A SCATCHARD PLOT TO CALCULATE KD AND R0))
I think it dangerous to eliminate outlier data points out of hand. Unless you have a very good reason to eliminate a data point (human error during the taking of that data point), then I think all data points should be included.
thanks for the reply
As I am producing a graph with the data it is clear that 1 of the points is an annomoly, therefore i didnt include it. Maybe the error should be included, however it causes the graph and results not to fit the trend if i do,
still not decided
If you repeat the experiment, does the anomoly still show up?
i didnt actually do the experiment
the data was given to me, and my task is to produce a binding plot, a scatchard plot and a linweaver-burke and then calculate Kd and Ro>> then compare them to each other.
btw how do i calculate R0...I caluclated Kd by Kd= 1/gradient(slope)
take a quick look if u can.
Can't open the rar file. Here is a good scatchard plot websitewww.curvefit.com/scatchard_plots.htm
I'm going to move this discussion to the biochemistry forum to get more help.
ok i could send you the excel file.
thanks ive looked at that link many times
The slope of a scatchard plot is -1/Kd
If you plot specific activity of the ligand bound recetor[LR]/[ligand] on the Y-axis and specific activity [LR] on the X-axis, the initial concentration of receptors [Ro] is the concentration at which the linear plot intersects the X-axis
I calculated Kd = -1/ gradient(slope)
-1 / - 0.1279 = 7.81 = Kd
Can i send you the excel file, its in Book 1 above.
Do do i know when it crosses the x-axis do i rearrange the line equation: y= -0.1279x+0.0225 and keep y as 0?
then that would be R0 = 0.1759 (units?)
I got the xls file thanks
by your fit with the outlier removed, then yes you have the corect R0 of 0.1759 units (pmol/µg ?)
Was the outlier greater than 2x the standard deviation of the mean for that concentratoin when it was included? You could present the data with and without it included and explain the criteria you used you exlude it in the relevant plots.
On the Lineweaver-Burk Plot of 1/[L] on the x axis and 1/[LR] on the Y axis, then the x intercept is -1/Kd and the Y intercept will be 1/R0 (or 1/Bmax)