Product description. "These syringe filters offer a choice of filter media: hydrophobic PTFE membrane for exceptional chemical and temperature compatibility -hydrophilic nylon membrane for excellent chemical compatibility with esters, bases, and alcohols, without prewetting -GHP (hydrophilic polypropylene) membrane for low protein binding -and hydrophilic PVDF (polyvinylidine fluoride) membrane for use in aqueous and nonaggressive, solvent-based mobile phases.