Our investigatory project for this year is entitled "The Antimicrobial Effect of Helianthus annuus on Escherichia Coli". I will be needing H. annuus extracts. I understand that there are a number of types of extracts and extraction methodologies. Which type of extract must be used for microbial assay? And which methodology should be used? A link would be very helpful ^___^. Thank you!