Making a stock solution for my drug using DMSO - (Oct/15/2013 )

mdfenko on Tue Oct 15 12:47:57 2013 said:

 

Frazermb on Tue Oct 15 12:25:01 2013 said:

If I weight out 2mg and add it to 1ml DMSO that will give me a final concentration of 4mM?

 

Then if I wanted to use 20ul of 0.1mM for my experiment I would dilute my stock x40 (1ml in 40ml ) to make 0.1mM?

yes, 2mg in 1ml will make ~4mM, but phage434 is correct, when you have so little it is best to just add solvent to the bottle and use the whole thing (if the bottle has not previously been opened).

 

if you have a 4mM stock then 1ml made to 40ml will be 0.1mM.

 

Yes sorry 1ml made up to 40ml.

I was thinking that if the drug is 10mg in bottle I could add 20ml solution (possibly DMSO) to make a 1mM stock?

Then if I wanted a 0.1mM solution for my experiments I would take 1ml and make it up to 10ml ? 

Is your 10mg bottle large enough to hold 20ml?  Why not make a more concentrated solution say a 10mM or 20mM stock and then take 100ul or 50ul to make your 10ml solution.  It will minimize the effects of your solvent....

Missle on Tue Oct 15 12:58:40 2013 said:

That makes sense.  Then your stock solution (in DMSO) has to be at least 200x concentrated >20mM.

So to make a 20mM stock I would need to add just 1ml DSMO to 10mg of drug?

Missle on Tue Oct 15 13:09:09 2013 said:

Is your 10mg bottle large enough to hold 20ml?  Why not make a more concentrated solution say a 10mM or 20mM stock and then take 100ul or 50ul to make your 10ml solution.  It will minimize the effects of your solvent....

Probably not now that I think about it. I think it may well be a approx 5ml, maybe. 

So if I make a 20mM stock I could use 1ml DMSO. I could then take 5ul and make it up to 1ml (buffer or media) to have a concentration of 0.1mM which I could then use 20ul for my experiment?

Yes, 10mg in 1ml would be ~20mM and 5ul into 1ml (a 200x dilution) would give a conc. of 0.1mM.

Thanks to everyone for the help its much appreciated.

Frazer

Hi,

So after speaking to my supervisorr I have been told that using up the full 10mg is not an option. They would like to keep some in case something happens and the drug is lost or spilt etc.

So I will be using either 2mg or 5mg of drug.

Also because one of my experiments will require me using 0.1mM of both cAMP and cGMP I would need a x400 concentration to which I can then make a x200 for experiment that only require either the cAMP or cGMP on its own.

So in keeping with the 5ul DMSO per 1000ul of media.

I will prepare my cGMP (500.14MWt) as follows:

2mg into 100ul for a 40mM or 5mg into 250ul for a 40mM. So when I am using the cGMP on its own I would need to just dilute it to 20mM. So if I'm adding 20ul for my experiment I will make 10ul stock upto 20ul by adding DMSO?

The calculations for the cAMP will be done soon as the drug is already been made soluble to possibly to 20mM. I am awaiting clarification.

Thanks

Frazer