Computational design of yeast synthetic gene circuits

I this work we firstly proposed lateral-flow assay combined with primer extension (PEXT) and gold nanoparticles to SNP genotyping of tmigd1 gene in Tsaiya duck which has advantages of easy operation, cost effective and time saving. The gold nanoparticles were tailed with thiol-(dT)30 using salt-aging method at 25 oC and used as label of lateral-flow assay. The lateral-flow device is mainly composed of test and control zone on the nitrocellulose membrane containing streptavidin and d(A)30, respectively. When the specific SNP exists, the corresponding primers can be extended, and then the reaction product will be able to be captured by streptavidin in the test zone due to the introduction of biotin-dUTP into the reaction product during PEXT. Gold nanoparticles will hybridize with reaction product to make it become visible. Here we reported the optimized parameters of Mg2+ in PEXT reaction and streptavidin on membranes to detect the signal specificity. In addition, it is found that increasing amount of PCR product and PEXT reaction cycle number result in the increase of the signal intensity without observable change of signal specificity.