Johnson Test Papers offers a complete line of high quality chromatography, electrophoresis and blotting papers for use in gel transfer applications and chromatography techniques. These products are available in many grades with different thickness and flow rate characteristics, optimised for your specific application and come in a variety of sheets, reel, and circle sizes.
These uniform, smooth, white sheets are produced from the specially selected, highest quality cotton linters with no additives and are widely used around the world, thanks to the purity, high quality, high value standard and consistency. This guarantees low ash content and the almost total absence of metallic contaminants, especially of Fe and Cu, which could lead to interferences.These qualities are relied upon by chromatographers and are essential to successful, reproducible chromatography. The raw materials used give these papers perfect structure and regularity in the distribution and position of the fibres, allowing perfect uniformity of the physical properties of each grade.
They undergo rigorous quality control when being manufactured, for characteristics important to the chromatographer and are tested specifically for chromatographic techniques to ensure uniformity within the grade. Likewise, correct storage of the paper guarantees its good behaviour later in the laboratory. The chromatography paper product line includes standard cellulose and ion exchange grades.
Johnson Test Papers’ family of absorbent papers come in different weights in grams and thickness for blotting procedures such as transport of samples, absorption of liquids in laboratories and protection of surfaces.
All types of blotting paper are available in sheets precisely cut to the most popular gel and transfer membrane sizes, allowing ‘out-of-the-box’ usage and eliminating sheet-to-sheet variations.
Our pure cellulose blotting papers are manufactured from the highest quality cotton linters using ultra pure RO water with no additives to ensure that no contamination will occur during the transfer steps. This high purity alpha cotton cellulose reduces background noise and interference in the detection system and has a perfect level of resistance to the moist stage, without the fibers loosening.The filter papers are manufactured and tested specifically for chromatographic and blotting techniques. This supports the wicking capability and uniformity of capillary action that is important for obtaining clean and even transfers during blotting.
The applications are very extensive: teaching, organic chemistry (separation of ions difficult to identify), research and biochemistry. In the field of biochemistry, its application is emphasised in the identification of components in samples of nucleic acids (DNA and RNA) and proteins by means of techniques of transfer by blotting and electroblotting. Usual methods by the moist (tampon deposit) or semi-dry method, in combination with cellulose nitrate or nylon membranes (Southern, Northern and Western blots, electroblotting and electrophoresis) are used for the separation of substances from a mixture according to the principle of distribution by velocities of aspiration. This is determined by the different sizes of the molecules, coefficients of distribution and molecular loads. In medicine, the process of blotting is used to detect the presence of disease-related proteins or viruses (e.g BSE or HM).
The most important parameters that indicate to us the properties of paper for chromatography are the weight in grams, the thickness and the speed of aspiration. While a paper of greater weight in grams and thickness guarantees a high load of solutes, the speed of capillary aspiration does not guarantee better definition but the contrary. For this reason, a slow paper will always have a greater resolution.