Abstract

• Bio-SELEX allows the identification of new biomarkers from biological samples. • Three steps are essential to perform Bio-SELEX; 1) Traditional SELEX, 2) Pull down, and 3) Mass spectrometry. • Bio-SELEX strategy allows the identification of biomarkers for infectious and non-infectious diseases. The SELEX strategy was discovered in 1990 by two groups of independent researchers [Tuerk and Gold 1990; Ellington and Szostak 1990]. This technique makes it possible to obtain aptamers, which are ssDNA and ssRNA molecules, which adopt unique three-dimensional (3D) structures allowing them to recognize specific targets with high affinity and specificity. Since then, the creation of multiple variations of the SELEX technique has evolved. Negative-SELEX [Ellington and Szostak 1992], Counter-SELEX [Jenison et al. 1994], Capillary electrophoresis SELEX (CE-SELEX) [Mendosa and Bowser 2004], Microfluidic-SELEX [Lou et al. 2009], Cell-SELEX [Daniels et al. 2003] are some of the variants that, based on advances in molecular biology, biomedical engineering, and biotechnology have improved the time of acquisition and the ability to recognition of the aptamers by different types of targets. Our research group has been developing a variant of the SELEX strategy that can be adaptable to multiple studies. Therefore, we report a new SELEX strategy modification to identify new biomarkers from biological samples called Bio-SELEX. The word Bio refers to the search for biomarkers and the biological nature of the samples used to obtain them.