We have a collection of inoculated MicroGard filters (see link) and we would like to extract DNA from those. Thus, we are looking for a good procedure to do so. We have experience in extracting nucleic acids from different membrane filters and could adapt those protocols, but the MicroGard filters are very thick and I am wondering if there's a preferred protocol to apply for best efficiency. We are glad to receive some suggestions. Have a great time, thanks! :)

http://www.carefusion.de/pdf/Respiratory/Pulmonary_Function_Testing/V-791711_CPR_MicroGard_II_EN_V03.pdf