Filtration methods are now above and beyond simple nylon membranes. Today’s devices represent the creation of new materials built into a wide variety of tubes and other receptacles for each one of the myriad of filtration needs.
While still available, membranes and devices that relied on amalgams of cellulose left researchers in want of a better system. These earlier filters had low flow rates, a tendency to bind to proteins, and low throughput that filtered a relatively small amount of sample before its pores became clogged. Innovations over the decades have resulted in an assortment of filters that come with their own sets of pros and cons. Nylon provides higher flow rates, but also tends to bind protein. Conversely, polyvinylidene difluoride (PVDF) doesn’t bind protein, but has frustratingly low flow rates. Polyethersulfone (PES) was the first to provide higher flow rates, low protein binding tendency, and a higher capacity.
With varying levels of chemical reactivity, airflows, surface tension, and physical structures, the materials differ in the types of solutions they can filter. If you’ll be filtering an aqueous solution, consider PES. Nylon, which is naturally hydrophilic and chemical resistant, might be a good choice if you’ll be filtering aqueous or organic solvents, such as those for HPLC. Or, try polyetrafluoroethylene (PTFE) if you’re dealing with hydrophobic mixtures.
You should also investigate other characteristics of the filter membrane. Ask about the distribution of pores in the membrane to determine the speed of filtration. If you’ll be filtering cells, find out if the membrane’s surface is smooth enough to prevent cells from being trapped. The size of the pores dictates how much pressure you’ll need to apply during the filtering process.
The market offers products for filtering all sorts of solutions and substances. You can find an assortment of filtration devices for sterilizing growth media. Or, you might be interested in filtering chemicals out of your protein sample. Other products include those that filter out viruses, concentrate solutions, and extract specific proteins.
Take a look below to find out about the types of products that await your attention. You might discover the filtration device that opens up a whole new world of productivity and success.
As testing equipment becomes more sensitive and industry regulations become more stringent, labs must have complete confidence that their point-of-use water systems will provide them optimum water quality, every time. Cascada systems employ Pall’s advanced water purification technologies to achieve the highest purity water through a series of separation and purification steps in a single benchtop box. For ultra-pure water, choose the Cascada BIO-water polishing system for demanding life sciences applications or the Cascada AN-water polisher for analytical applications. The Cascada RO-water pretreatment system is a reliable way to protect and extend the life of the polishers.
The ProteoExtract™ Protein Precipitation Kit provides a fast and efficient method to concentrate and clean up proteins from a variety of sources. Detergents, chaotropes buffer reagents, salts and other interfering compounds stay in solution. Precipitated proteins can easily be re-suspended in the buffer of choice for a wide range of proteomics downstream applications such as isoelectric focusing (IEF), 2DGE, 1DGE or for tryptic digestion prior to mass spectrometry and peptide separation schemes
