how can i have a good calibration curve r^2 value?

Question

calibration curves are mainly used in determining the precisio of your measured values. how can i have a good result in my calibration curve?

Answer 1

A good calibration curve is dependent on a ton of factors. Mainly it depends on what you do to your sample before you measure it. The first thing you need is a very accurate measuring device for spiking your calibration control standards most of the time we use pipettes. If these are inaccurate then your curve is most likely going to show it. Also, you have to make sure you instrument response is linear for the range of measurements you are making. If it isn't then you can only use the linear portion of the curve. The main thing you need to be careful with is how you handle your samples before you measure them, any accidental errors you make will show in your curve. Just try to be as careful as possible

Answer 2

You need good quality data and lots of it.
Make sure that the standards you are using e.g solutions are properly prepared.
Have at least 9 points for the linear regretion
Make sure that your measurements are within the linear range of the method E.g. for OD is better to dilute your samples so that the reading is <1.0 and actually the best region for OD is 0.2-0.8.

Points corresponding to low values on x axis (usually concentration)tend to have a larger effect on the slope (and r^2) than the higher ones. I don't remember why-one of my physical chemistry professors told me that once upon a time. So bias a bit your sampling instead of dividing the concentration region you are using in egual intervals.

Obviously you need to be very careful when conducting the experiment

Answer 3

Only if you get the right results in your experiment.