In addition to the standard economy selection of tip-filters for HPLC ProFill, La-Pha-Pack now offers a new ProFill PLUS line of products with filters with an integrated glass fiber pre-filter. The PP housing of these filters encase in fact two filters: the membrane of the pre-filter made of glass fiber with a pore size of 1 - 2 µm dedicated for the pre-filtration of the larger particles for samples with a heavy load of particles, and the final membrane for the fine filtration. The pre-filter of glass inhibits a clogging or rupture of the fine membrane, which is made of regenerated cellulose, nylon (PA), PTFE or PVDF in pore sizes of 0.2 µm or 0.45 µm. The ProFill PLUS series of syringe filters are designed for a higher operating pressure, i.e. up to 7 bar (= 700kPa), which was achieved by a special injected sealing of the casing, which guarantees that the liquid will not flow around the membrane. The casing is color-coded and carries the exact type of membrane and its pore size in plain text, which inhibits the possibility of mistakenly use, and increases the security of the results. There is a model of this series of 25 mm ProFill PLUS HPLC syringe filter with only a membrane of glass fiber, and may be installed before the standard filter as an additional filter. All 25 mm filters of ProFill and the ProFill-PLUS series come in packages of 100 units in a tamperproof original bag with Minigrip, which is additionally secured by a re-saleable PP box.