The Millicup vacuum-driven bottletop filter unit is a disposable device that provides a fast, effective, and safe means to filter mobile phases and running buffers used in instrumentation analyses (for example, HPLC). The Millicup vacuum-driven bottletop filter unit eliminates the risk of contaminant carry-over from solvent to solvent. Unlike reusable filter holders that must be washed and assembled before each use, Millicup units require no assembly or clean-up. If accidentally dropped, the Millicup vacuum-driven bottletop filter unit will not break, ensuring a safe environment in which to filter solvents and other hazardous solutions.