DNA aptamers against bacterial cells can be efficiently selected by a SELEX process using state-of-the art qPCR and ultra-deep sequencing
DNA aptamers generated by cell-SELEX towards bacterial cells have gained elevated curiosity as novel and cost-effective affinity reagents for cell labelling, imaging and biosensing. Right here we describe the choice and identification of DNA aptamers for bacterial cells utilizing a mixed method based mostly on cell-SELEX, state-of-the-art functions of quantitative real-time PCR (qPCR), next-generation sequencing (NGS) and bioinformatic knowledge evaluation. This method is demonstrated on Enterococcus faecalis (E. faecalis), which served as goal in eleven rounds of cell-SELEX with a number of subtractive counter-selections towards non-target species.
Throughout the choice, we utilized qPCR-based analyses to guage the ssDNA pool measurement and remelting curve evaluation of qPCR amplicons to watch adjustments in pool variety and sequence enrichment. Primarily based on NGS-derived knowledge, we recognized 16 aptamer candidates. Amongst these, aptamer EF508 exhibited excessive binding affinity to E. faecalis cells (OkD-value: 37 nM) and efficiently discriminated E. faecalis from 20 totally different Enterococcus and non-Enterococcus spp. Our outcomes show that this mixed method enabled the speedy and environment friendly identification of an aptamer with each excessive affinity and excessive specificity. Moreover, the utilized monitoring and evaluation methods present perception into the choice course of and could be extremely helpful to review and enhance experimental cell-SELEX designs to extend choice effectivity.
Actual-time quantitative PCR (RT-qPCR) is the gold commonplace to quantify the BCR-ABL1 transcript for molecular response monitoring in power myeloid leukemia (CML) sufferers, and it performs a pivotal function in medical decision-making course of, even when it presents technical limits. Growing knowledge counsel that digital PCR (dPCR) is extra correct and dependable than RT-qPCR in CML minimal residual illness monitoring and in sufferers’ choice for therapy discontinuation. However what concerning the identification of therapy discontinuation failures? We current the case of a CML affected person enrolled each in a research aiming to comparatively assess molecular response by RT-qPCR and dPCR and within the progressive arm of the OPTkIMA trial. It is a part III trial together with CML sufferers randomized to obtain a hard and fast versus a progressive intermittent tyrosine kinase inhibitor routine. At 24 months, due to two consecutive detections of MR<sup>2.0</sup> by RT-qPCR, the affected person resumed day by day therapy.