Research / 2021 / Article / Fig 3

Research Article

Low-Cost and Scalable Platform with Multiplexed Microwell Array Biochip for Rapid Diagnosis of COVID-19

Figure 3

The performance of the RT-LAMP system for the detection of ORF1ab plasmids on a multiplexed microwell array and a real-time PCR instrument. (a) Real-time amplification curves with serially diluted targets ranging from 102 copies/mL to 109 copies/mL (1-4, normalized real-time amplification curves) and ddH2O as negative control: (1) 109 copies/mL (black line); (2) 107 copies/mL (red line); (3) 105 copies/mL (blue line); (4) 103 copies/mL (pink line); (5) 102 copies/mL (orange circle); (6) negative control (cyan circle). (b) The threshold time as a function of the target concentration. The data was fitted with linear regression against the logarithm of the concentration. Error bars represent the standard deviation of 3 independent repeats. (c) Images of the multiplexed device taken after 25 min incubation for the detection of the virus at 109, 107, 105, 103, 102, and 101 copies/mL, respectively. The results show a detection limit of 103 copies/mL for ORF1ab plasmids. (d) Comparison of reaction times of the RT-LAMP amplification in the microwell array chip (black line), in the tubes (red line), and in the 96-well plate (blue line) with serially diluted target ranging from 105 copies/mL to 1011 copies/mL.