Research Article

Selection of DNA Aptamers for Ovarian Cancer Biomarker CA125 Using One-Pot SELEX and High-Throughput Sequencing

Figure 3

Representative agarose gel image showing the results of cycle determination, PCR positive and negative controls, and One-Pot negative control. The optimal number of PCR cycles is determined by removing reaction tubes from the thermocycler at regular intervals and electrophoresing the reaction mixtures together on a gel. In this case, 21 PCR cycles gave desired PCR product with minimal formation of more slowly migrating byproducts. The gel image also shows that positive and negative PCR controls give the correct outcome (product and no product, respectively). Finally, the One-Pot negative control shows that tubes to which no DNA was added do not give any PCR product, as expected.