DNA / RNA Purification:
The purification of Genomic DNA, Plasmid DNA, Nucleic Acids or RNA is a very complex process that require high purity and quality materials. Ahlstrom offers a range of glass microfiber materials for use in DNA/Genomic. Manufactured for OEMs, used in purification kits, Ahlstrom products are found in spin columns and assay plates throughout the world.

Qualitative:
Ahlstrom qualitative grades of filter paper are, by definition, recommended for use in analytical methods, which determine or identify particulate constituents of a mixture irrespective of the amount present.

Applications using filter paper in a system under pressure or vacuum require the use of a high wet strength grade. These grades contain a small amount of chemically stable, insoluble binding resin that strengthens the natural fiber to fiber bonds under wet conditions. Grades containing wood fiber or resins are not recommended for use in quantitative ashing techniques.

Quantitative (Ashless):
Ahlstrom manufactures a line of extremely high purity, acid washed paper designed for use in analytical applications and gravimetric analyses. We manufacture these quantitative grades from 100% high quality cotton fibers using ultra-pure, reverse osmosis water. A final acid treatment removes remaining organic or inorganic impurities. All quantitative grades have a maximum ash content of 0.012%.

Specially treated, hardened ashless papers are available for applications requiring increased wet strength and handling capacity. These hardened grades with a tough, smooth surface free of loose fibers, are ideal for collecting wet precipitates.

Pleated (fluted) :
Ahlstrom pre-pleated grades can save valuable time and maximize the efficiency of your filter system. Pleating increases the effective surface area increasing flow rate and loading capacity thus decreasing filtration time. We offer a full range of pleated filters to meet your needs from grades with rapid flow rates for filtration of viscous materials to grades with tight matrices for removal of fine precipitates. Pleated circles are available in 12.5 cm to 90 cm diameters.

Glass Microfiber Filter:
Ahlstrom offers a full range of glass fiber filter paper manufactured from borosilicate glass including Binder Free Glass Filters, Glass Fiber with Added Binder, and specialty laminates. The unique characteristics of glass fiber filter paper make its use advantageous in specialized applications. In particular, glass fiber filter paper has the following notable properties:

• Rapid Flow Rate - Movement of liquid laterally along the fibers and vertically through the filter and a lack of porosity and swelling of individual fibers combine to provide maximum flow efficiency.
• Fine Particle Retention - By combining different fiber diameters, various pore sizes and distributions can be attained. The retention range of Ahlstrom's Glass Fiber Filter Papers extends downward to 0.7 µm for maximum filtration efficiency.
• High Loading Capacity - Unlike cellulose filters whose fibrous matrices clog rapidly when filtering high particulate solutions, glass fiber filter papers will continue to filter a much greater volume prior to loading.
• Chemical and Thermal Resistance - Glass fiber filter papers maintain their operational integrity in the presence of acids, alkalis, most organic solvents and to temperatures of 500°F.
• Long Shelf Life - Glass fiber filter papers do not absorb moisture and will not harden or yellow. Under normal conditions these filters can be stored indefinitely.
• Binder-Free Glass Microfiber Filter These grades contain no binders or other additives that may cause interference in sensitive enzymatic or other chemical reactions. Ahlstrom Binder-Free Glass Fiber Filter Papers are ideal for use in water and wastewater analysis, gravimetric analysis involving ignition of the sample and filtration of hot gases and liquids.

Glass Microfiber Filter with Binder:
Glass fiber grades with added binder are ideal for use in applications requiring a stronger sheet with greater handling capability. The addition of a small amount of binder significantly increases the wet and dry strengths of the material making them particularly suitable for pleating and mechanical handling.

Polyshield® (Fluid Barriers):
Ahlstrom fluid barriers are super absorbent, pure cellulose papers with an impermeable polyethylene backing that absorbs splatters and spills, and protects work areas from contamination and damage by toxic, infectious, corrosive, radioactive or staining materials.

Sugar Testing Paper:
Ahlstrom manufactures three (3) grades designed specifically for use in the sugar industry. All three grades are available in sheets, circles and rolls cut to fit your particular application.

Asphalt Testing Paper:
Ahlstrom high purity filter papers, are commonly used for asphalt testing in extraction units. These quality papers combine good retention (4 µm) with moderate flow rates. They are available in solid circles, circles with precut center holes, sheets and rolls. Circles and sheets are shrink-wrapped in packs of 100 for protection from moisture and dust.

Seed Testing Paper:
Ahlstrom manufactures grades of non-toxic pape