How to plot a dose response curve and measure EC50. Key concepts in pharmacology.

To understand the pharmacology of a drug we need to know how tightly it binds to its receptor and how effective it is at producing or inhibiting a response. These proerties are measured from concentration (or dose) response curves. This involves measuring responses to a drug at different concentrations and plotting the responses on a graph against the concentration of the drug. From the plot you can measure EC50 (or ED50) and maximum response. This video takes you through the steps involved in plotting a concentration (or dose) response curve and log concentration (or dose) response curve, and explains how to extract EC50 (or ED50) values.
#drug #ec50 #ed50 #drc #agonist #receptor #pharmacology

[@tatatachaaaaan]

First time I see such a clear explanation, thank you so much for your video

[@Simba97]

Hey Professor G, thanks for your help! Really going to help with my Pharmacology Prac tomorrow.

[@MoonManAK]

Thank you so much. Simple and clean

[@professorGpharm]

You're welcome!

[@josephperry93]

Thanks for the video. What song was used for it? Very catchy

[@47Yeoman]

Elegant presentation. Thanks ... J

[@paulvillagran7501]

ty so much man

[@infinitefury4414]

Thanks a bunch

[@nooneyouknowof5105]

Is graphpad prism the only software you can use to calculate EC50? I'm a student and my research group and I can't afford to buy it:(

[@professorGpharm]

Almost any graph plotting software should do. If you don’t have access to a good package, you can draw the graph by hand on a piece of paper and read off the EC50.

[@nooneyouknowof5105]

@@professorGpharm is excel accurate?

[@rydonwunali]

Hi I need your help when I try to plot the log concentration on the x and the response on the y I keep getting a straight vertical line. I am not getting the line that you are getting in your second graph any ideas?

[@MaestroAssistant]

rydonwunali this is probably because you need to test more drug concentrations on both the minimum and maximum end. Try adding more points in both directions so that the drug reaches no effect (min) or saturated effect (max).

[@josephnseke757]

amazing

[@jadeantonia9813]

hi, my concentrations in the question im doing range from 0.01 and 100. This means i have to plot some negative figures on my graph but that doesnt seem right to me. how do i go about this?

[@steves1015]

Considering the amount of time since your comment I assume you have solved this issue :). But for anyone reading, negative numbers for log(concentration) is fine. It just means you are using concentration values less than 1, since crudely speaking logarithm to base 10 tells you where the number “starts” relative to the decimal point. If you are uncomfortable with the negative numbers you can get the numbers to be all positive if you change the units for your concentration. For example, in this example you say you have concentrations of 0.01 and 100 - let’s say your units are in microMolar. Without changing then these values would become -2 and 2 after taking the log (base 10). You can then change these values to both be in the nM scale by multiplying by 1000. So you’d get 10nM and 100000nM. Now if you take the log of these values you would get 2 and 5 respectively. What is more important is to make sure you are consistent with the units, and know how to successfully convert back from the log(concentration) value to the actual concentration.

[@rinkiarya9644]

Thanku

[@zainabbaqer4713]

thank you but the log of drug concentration should be labeled not normal concentration

[@steves1015]

If you are talking about on the second graph with the semi-logarithmic paper, then yes it should, since you can read the concentrations directly from the graph using that form of paper. No conversion is necessary.

[@rinkiarya9644]

Thanku