I am currently trying to do a minimal inhibitory concentration assay using the bacteria staphylococcus aureus. I will be using different concertation of a mixture of metal nanoparticles which i need to disperse in water or another solvent to make stock solutions. The problem is that the nanoparticles are water insoluble and do not make a homogenous mixture. What solvent can i use in my case that will not influence the MIC. I will learn to composition of the nanoparticle mixture soon as i have not yet been fully informed.