Clean-up is a critical step in a sequencing workflow, preparing DNA or RNA samples to be compatible with a sequencer. Sanger Sequencing, also known as Capillary Electrophoresis (CE) sequencing, is a method of DNA sequencing, based on the selective incorporation of fluorescent dideoxynucleotide chain terminators (dye terminators) by DNA polymerase during in vitro DNA replication (cycle sequencing). As sequencing is a highly accurate technique based on reading a DNA sequence base by base, it is very important to have an effective clean-up of dye-labeled extension products in the reaction mixtures, eliminating interference of unincorporated dye terminators, desoxynucleotides and salt-ions after Sanger cycle sequencing. This prevents their co-injection with sequencing products during Capillary Electrophoresis.
Clean-up of PCR samples prior to sequencing and removal of dye terminators post cycle sequencing can be performed using magnetic bead, resin-based, and enzymatic methods. In most instances, a magnetic bead-based chemistry is utilized to generate capillary electrophoresis-ready and sequence-ready samples.