DNA aptamer against EV-A71 VP1 protein: selection and application

Figures

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  Fig. 1. The predicted second structure of aptamer V7, V11, V21. The predicted second structure of aptamer V7 (a), aptamer V11 (b) and aptamer V21 (c)

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  Fig. 2. The ELISA for the affinity measurements of three aptamer candidates against EV-A71 VP1 and CA16 VP1 selectivity. BSA played as the negative control (NC). The errors were calculated from three repeated experiments

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  Fig. 3. The dissociation constant (Kd) values of aptamer candidates for EV-A71 VP1 protein, were measured by ELISA. The Kd value of V7 (a). The Kd value of V11 (b). The Kd value of V21 (c). The values of OD450 and Kd represent the mean ± SD of three independent experiments

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  Fig. 4. The Schematic illustration of the chemiluminescence aptasensor

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  Fig. 5. The confirmation of the integration of aptamer and magnetic beads by flow cytometry. Contrast naked MBs (a). V21-MBs complex (b)

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  Fig. 6. The detection for different samples. Hanks storage solution was adopted as the negative contrast. The values of CL intensity represent the mean ± SD of three independent experiments. Data were obtained from three separate experiments and are presented as the mean ± SD. **Means P < 0.001

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  Fig. 7. The inhibition of EV-A71 infection by aptamer V11 and V21 in RD cells in vitro. EV-A71 was firstly pretreated by PBS buffer, random ssDNA library, aptamer V11 and V21 respectively at room temperature for 30 min. Then RD cells were infected with treated EV-A71 through incubation at 37 ℃ for 60 min. After renewal of the culture solution to remove free virion and aptamer, the RD cells were cultured at 37 ℃. a The CPE of RD cells were observed under optical microscope at 72 h post-infection. The normal untreated RD cells were adopted as the mock group. b RT-qPCR analysis was performed to detect EV-A71 mRNA in RD cells infected by original EV-A71 (PBS), random ssDNA library-medicated EV-A71 or aptamer-medicated EV-A71 at 24 h post-infection. c The expression of EV-A71 VP1 protein in RD cells infected by EV-A71 with different treatment at 48 h post-infection. The β-actin protein was employed as the internal reference protein. Data were obtained from three separate experiments and are presented as the mean ± SD. *Means P < 0.05; **means P < 0.001