According to various embodiments described herein, a microfiuidics-chip based purification device and system for Sanger-sequencing reactions is provided. The device and system allow for the introduction into a sequencing system of a cartridge containing purification technologies specific to the sequencing contaminants or sequencing method where the simplified purification solution of a cartridge allows automation of the sample purification process, reduced consumption of purification reagents, and consistency in sampling by reducing the sampling errors and artifacts. These various embodiments therefore solve the need for a microfiuidics-chip-based, Sanger-sequencing reaction purification system for CE devices. The microfiuidic chips described can be used as a PCR chip by reorganizing the on-chip reagents, reaction wells and work flow steps.