CONCENTRATION OF DMSO IS TOO HIGH - what can I do? (Oct/05/2006 )

I'm stuck on this thought...can you please reason with me and see if you can offer a solution...

I am doing cytotoxicity assays with plant extracts (which are extracted using methanol). I have been preparing new extracts and I will be dissolving them in DMSO (after evaporating off the MEOH). In the past I've used 100% DMSO to dissolve my plant extracts and this posed a problem because it was having a toxic effect on my cells, as a result I had to dilute my extract so much to get it to 0.1% that i had to use such a high volume to arrive at the drug concentration I needed.

Well now I am going to dilute the DMSO prior to adding it to the extract because my objective is to keep the extract as concentrated as possible. problem: I don't know whether to dilute with complete media (because of what effects the media components may cause) or with water... if i dilute with water, the non polar components of my extract may not dissolve, so I don't know what to do. Since I am going to be using DMSO also as a control treatment in my experiments, would I dilute DMSO with complete media or water for my wells? what can i do to keep the conc. of DMSO low and the conc. of my plant extract high without having to use 50mls of the extract in a well...

I'm stuck on this thought...can you please reason with me and see if you can offer a solution...

I am doing cytotoxicity assays with plant extracts (which are extracted using methanol). I have been preparing new extracts and I will be dissolving them in DMSO (after evaporating off the MEOH). In the past I've used 100% DMSO to dissolve my plant extracts and this posed a problem because it was having a toxic effect on my cells, as a result I had to dilute my extract so much to get it to 0.1% that i had to use such a high volume to arrive at the drug concentration I needed.

Well now I am going to dilute the DMSO prior to adding it to the extract because my objective is to keep the extract as concentrated as possible. problem: I don't know whether to dilute with complete media (because of what effects the media components may cause) or with water... if i dilute with water, the non polar components of my extract may not dissolve, so I don't know what to do. Since I am going to be using DMSO also as a control treatment in my experiments, would I dilute DMSO with complete media or water for my wells? what can i do to keep the conc. of DMSO low and the conc. of my plant extract high without having to use 50mls of the extract in a well...

Thanks alot!

1% DMSO doesn't cause any toxicity to cells but we generally use 0.5% DMSO, final concentration.

To keep the final concentration to 0.5%, you can make 200x stock in 100% DMSO.

Or to keep the final concentration of 1% DMSO, you can use 100x stock in 100% DMSO.

Hope it helps.