Abstract
Earlier, we described a series of allosteric aptamers containing no chemical modifications and showing fluorescence changes upon binding simultaneously malachite green (MG) and target analytes, such as adenosine triphosphate (ATP), flavin mononucleotide (FMN), and theophylline (TH) [1]. The aim of the present study is to develop similar analytical system with aptameric sensors conjugated to microspheres for multiplexed assays. We used standard FACS Calibur (BD Biosciences, San Jose, CA) flow cytometer to measure the formation of fluorescent MG complex with its aptamer on beads in response to binding of different analytes. We developed sensors for FMN, thrombin, TH, tobramycin and ATP, all changing fluorescence intensity in a dose-dependent manner. The potential of described flow cytometry based multi-assay was confirmed in simultaneous measurements of thrombin (0.1 - 10 uM), TH and ATP (0.01 - 1 mM).