What is the solution when tween80 or DMSO is not enough to dissolve plant extrac - (Jun/15/2010 )

Hi,
I'm stuck on this thought, can you please help me!?

I'm study the effect of some plant extracts (by organic solvent : hexan. chloroform, EA and methanol) on nematode larvae.... I have to use just 3% of DMSO or Tween80 to dissolve 5 grams of extract to prepare 100ml of 50mg/ml extract as stock by dissolving 5g of extract in 3ml of DMSO or Tween80 and add 97ml distilled water and then I'll use this concentrations 50, 25, 12.5, 6.3 and 3.2 but the problem is 3ml is not enough to dissolve 5g of extract and If I add more DMSO OR Tween it'll be toxic for the larvae?

So, how to solve this problem

Ahmed

try mixture of both tween/dmso? or first the solvent then surfactant?