Membrane Filters

DHI LAB Products is a supplier of GVS filters (former Poretics)

Cheap prices on filters, please see our pricelist

• Polycarbonate filters, especially suitable for e.g., size fractionation of water samples
• Black polycarbonate filters, especially suitable for e.g., epifluorescence microscopy
• Teflon PTFE syringe filters, especially suitable for filtration of organic samples for HPLC, gas, 
  strong acids and aggressive solutions

GVS, former Poretics, Polycarbonate Membrane Filters (PCTE)

• Smooth thin glass-like surface with cylindrical pores capturing 100% of cells larger than pore size 
• Ideal for particle identification by microscopy
• Precise pore sizes and pore distribution for absolute filtration and separation
• Negligible absorption and adsorption

GVS, former Poretics, Black Polycarbonate Membrane Filters (PCTE)

• Zero auto fluorescence, ideal for epifluorescence microscopy
• Permit phytoplankton, bacteria, yeasts, etc to be visible
• Smooth surface plane for microscopy

The epifluorescence microscopy technique is used for the assay of microorganisms in water samples, food and dairy products, wines and beverages, and for general micro-biological laboratory, medical, and research purposes.

The basic procedure is simple and reproducible:

1. A known quantity of liquid is filtered through a black polycarbonate membrane
2. The microorganisms, e.g., bacteria, are stained on the surface of the filter or prior to filtering, while some organisms like algae show auto fluorescence
3. The fluorescing microorganisms are observed using an epifluorescence microscope

Most polycarbonate (PCTE) filters are in stock

GVS, former Poretics, Teflon PTFE Syringe Filters

• Non-sterile and hydrophobic
• Especially suited for HPLC samples
• Negligible absorption and adsorption

Teflon (PTFE) syringe filters, 0.2 µm pore size and 17 mm diameter are in stock. These are especially suited for pre-filtering solvent extracts prior to HPLC analysis.