Provided herein is a method of reducing a microbial infection of a heparinized surface wherein heparin precipitation is reduced as compared to a control. In some embodiments a composition comprising ethanol and isopropanol is applied to the surface. In other embodiments, two or more ethanol compositions are applied and removed sequentially from the surface prior to contacting the surface with a biological fluid, tissue or vessel, wherein the composition in each successive administration comprises an increased amount of ethanol. Also provided is a method of reducing a microbial infection of a surface comprising applying a mucilage extract from an Opuntia ficus indica species to the surface.