Cuning

Often the laboratory measurements of an RF value will differ from the published values for that particular substance. “Cuning” is a process of adjusting the laboratory values to match the published values.

The first step is to measure one or more control substances and compare the values to the published values.

Press the “+” button to select a control substance:




Double-click on the substance to be used as a control.




The values for the control substance will be displayed in the Cune form.

Next, enter the values you measured in your lab in the boxes below the window,


and click “Add to table”. The “Local” values for the substance (i.e. the values measured in the lab) will be displayed below the Published values.




It is recommended that you use more than one control substance to create the Cune values, ideally substances with quite different values.




At this point you may want to save the values in a “Cune file” so they can be used again, by clicking the disk icon on the form. However, as Cune values are typically unique to each plate, saved values should only be recalled for the plate they were derived from.



To apply the Cune values to your measurements, check the “Apply Cune” checkbox on the main form.






After adding a TLC spot, the measured spot values show on one line in gray, and the adjusted values on the line below in light blue. Substances are listed below the adjusted line that best match the adjusted values.




Note: The method to calculate the adjustment factors was developed by Bruce McCune, after whom it is named.