For the ordinary syringe filter, it is composed of two parts, housing and membrane, which can be made of different materials. Polypropylene is stable in nature and resistant to various solvents. Water system/organic system are classified according to the material of the filter membrane, which are respectively suitable for filtering aqueous solutions (for life sciences) and organic solutions (for chemistry).
The organic system should be used to filter aqueous solutions without any problem, but the water system may be dissolved by organic solvents, which is not suitable for the filtration of organic systems. 0.22 micron and 0.45 micron are frequently used filter membranes for the syringe filter. It is suitable for filtering small amount of liquid, large amount, or too much insoluble matter can cause clogging. It is commonly used to process HPLC samples, and it is also very convenient to use with Schlenk line.
Made of colorless polypropylene or polycarbonate with standard inlet and outlet connectors, sterile syringe filter can reduce unwanted peaks, improve the signal-to-noise ratio and extend the life of the column. There are aseptic packaging and medical grade packaging options, and a special tube outlet can be used for high-level sample separation and return to microtubes, avoiding air blocking. By filtering to remove all contaminated particles, the experimental results can be improved.
The sterile syringe filter is mainly composed of three parts, the filter container, the support basket and the filter bag. When the bag filter is used to filter liquid, the liquid enters from the liquid inlet on the side of the filter, and then rushes into the filter bag. In the whole process, the inner surface of the filter bag is evenly distributed, and the liquid passing through the filter bag is along the wall of the metal support mesh basket.
As the liquid outlet at the bottom of the sterile syringe filter is eliminated, the filtered particulate impurities are trapped in the filter bag, completing the filtration process. The larger membrane surface area of the sterile syringe filter increases the flow rate and throughput and meanwhile reduces the required pressure to empty the syringe. So it is easier to filter the solution. The color outer ring on the housing clearly marks the inner filter and the type of membrane.
The sterile syringe filter manufacture is carried out in a controlled environment and an automatic process. During the assembly process, the operator’s hands will never touch the filter. The "Quality Certificate" attached to each box describes quality standards. With the lowest protein adsorption, we can use this filter to filter the protein solution, and the filter membrane with larger pore size is used for clarification and pre-filtration. Adopting mixed cellulose ester (MCE) membrane, the sterile syringe filter can filter water, buffers or other aqueous solutions reliably and routinely, and a larger pore size filter membrane is used for clarification and pre-filtration.
The sterile syringe filter adopts medical-grade production equipment and a class 100,000 clean workshop. The air tightness test of each filter, the integrity test of each batch of product, the chromatographic analysis and the ultraviolet absorption contrast test easure the quality of the sterile syringe filter.
The smooth inner surface of the sterile syringe filter has no grooves, no dead corners, and easy cleaning; the leak-proof design, the filtrate will not bypass, and will not leak; the upper cover adopts a quick-opening design, which is convenient for customers to replace the filter bag; The bag has a handle design, which is easy to replace and clean and safe. The sterile syringe filter can replace the stainless steel filter within a certain range of the filtration field.
Filter material of sterile filter includes PES (polyethersulfone), Nylon66 (nylon 66), PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride). Large operating pressure of 13mm diameter is 7bar; Large operating pressure of 25mm diameter is 6bar. The sterile syringe filter uses a well-known brand of polyethersulfone filter membrane, which has strong hydrophilicity, an asymmetric structure, regular membrane pore distribution, and high flow rate. Compared with other filter membranes, it has the characteristics of low protein adsorption, low dissolution, high speed, and high flux.
The sterile syringe filter has a wide range of applicability. It is usually used for rapid sterilization and filtration of culture media, buffers and other aqueous solutions. However, due to differences in the temperature, concentration, contact time of the sterile syringe filter, and other factors beyond our control, the use of the filter device will be affected.
The main applications of sterile filters include two aspects, more suitable for filtering biological solutions with very low protein content; more suitable for cell culture medium and microbial culture medium, reagents and additives.