Abstract: A method and apparatus for testing a pharmacological IV admixture for contaminants, following filtering of turbid liquids such as emulsions through a micropore filter, includes the step of first air purging or gas purging residual emulsion particles through the micropore filter using pressure, before admitting a growth medium to the upstream side of the filter. The air purging of these emulsion particles, so that they are substantially removed from the upstream side of the filter, enables the successful sterility testing of the filter by admitting clear growth medium, waiting the required culturing time and observing for turbidity which evidences growth of microbes. The described procedure removes residual emulsion particles simply and effectively so that the visual test is effective. In a preferred embodiment the procedure is carried out using a sealed, sterile growth medium bag connected to the filter assembly, the bag having a quantity of sterile air along with the liquid growth medium.