For many non-sensitive applications, you can use a filter/no barrier or a standard pipette suction. Typically, LABS use these tips to load agarose gels, isolate plasmid DNA, and other similar applications. Barrier-free suction heads are a mainstay of any lab, and as a bonus, are often a less expensive option.

These suction heads come in bulk (i.e. in a bag), pre-packed (i.e. on a shelf that you can easily fit into a box), or easily reloaded, allowing you to easily reuse your shelf but avoid the pain of loading the bulk suction heads. While bulk and most reloads are not sterile, you can sterilize them and their storage boxes/shelves in an autoclave.

Aerosol barrier pipette tips prevent PCR contamination and help with PCR positive controls

The aerosol barrier suction head, also known as the filter pipette suction head, is equipped with a filter in the proximal portion of the suction head. Filters protect your pipette from aerosols and from inhaling volatile or viscous solutions into the barrel, all of which can contaminate and damage the pipette. These suction heads are usually pre-sterilized and do not contain DNase/RNase. For some of these techniques, however, "obstacle" is a bit of a misnomer. Only certain high-end suction heads provide a true sealing barrier. Most filters will only slow the flow of liquid into the pipette.

In addition, the filter cartridge suction is a good "training wheel" for novices. Many times pipette contamination occurs when a new lab member accidentally inhales fluid into the pipette itself. Throwing away the suction head is much easier and cost-effective than sending the entire pipette to be serviced because there is liquid in the piston.