Hi Maliha, It seems that you have to prepare test solution of the ethanol extract in DMSO for antifungal assay. For this you should first distill off ethanol and obtain crude plant extract free from ethanol. Then first determine MIC and based on the MIC value you can prepare test solutions of different concentrations (in % or ppm) by dissolving different quantities of extract in DMSO. Alternatively you can first prepare solution of higher concentration in DMSO and then dilute it to range of lower concentrations using DMSO as per your experimental requirement.
I'm afraid to tell that you have to test it until it dilute, but concentrations over 10-2 M may implicate in direct effects by DMSO in your experiments.
there is no growth of fungus in my petri plates after i apply different plant extracts . in control plate i just add water and media and no growth of fungus is seen . i use 2 gram of dry extracts iand dissolve it in 100ml dmso .