Systematic evolution of ligands by exponential enrichment (SELEX) is a well-established technology for the screening of aptamers binding to various targets with relatively high specificity and affinity. The screened aptamers have shown great achievements in bio-sensing and targeted therapeutics, which in turn stimulate continuous development of SELEX technology. To date, many SELEX technologies have been established, such as cell-SELEX, mag-SELEX, capillary electrophoresis SELEX and some novel modifications of SELEX. This review highlights current screening technologies and comprehensively pin...