Which sterilizing filter is used for medium volume solutions?

• A. Millipore Millex
• B. Millipore Stericup
• C. Sartorius Minisart
• D. Pall Acrodisc

Answer: (B)

Matching the filtration setup to the volume you need to process is essential. For medium-volume solutions, a bottle-top vacuum filtration unit like Stericup is ideal because it provides a ready-to-use, sterile path from the bottle (or container) through a 0.22 µm (typical) membrane into a collection vessel. This setup enables you to filter larger volumes quickly and consistently without repeatedly attaching syringes or reconfiguring parts, which is convenient for applications like media, buffers, or other solutions you’d filter in tens of milliliters up to near a liter or more.

Other options are more oriented toward syringe filtration or smaller-volume workflows, where you manually push solution through a membrane or assemble/filter in a less streamlined way. That makes them less suited for the middle-range volumes often encountered in routine sterilizing filtration, hence Stericup is the best fit.