Illustration of the 3-step PCR-ELISA method: (i) amplification of the gene of interest using PCR in the presence of DIG-dUTP, which is then bound to specific probes, (ii) immobilization of the gene of interest to the microplate through strong affinity of avidin-biotin interaction, followed by (iii) detection of biotinylated DNA using an anti-DIG-peroxidase conjugate with substrate ABTS to form a blue-green color reaction that is both visible and measured using a spectrophotometer.
