Obviously, C-line and T-line emitted fluorescence. However, this photo was taken without a UV filter, containing a strong background caused by the excitation light source. As a comparison, Figure 5a presents a QD lateral flow strip picture with a UV filter, which accepted little https://www.selleckchem.com/products/BIBW2992.html influence of the excitation light source, demonstrating that the UV filter is essential. Though the effect of the excitation light source was eliminated, the fluorescent intensity was also weak in detecting
a low-concentration sample (Figure 7a). The proper image enhancement algorithm played a critical role. In order to display our method’s superiority, traditional HE and WTHE algorithms were compared with the proposed algorithm (Figure 7). Figure 7b,c shows test strip images after processing of the traditional
HE and WTHE algorithms, respectively. The test strip image processed by the proposed modified WTHE algorithm is shown in Figure 7d. By comparing this method with other image enhancement algorithms, the results indicated that the proposed algorithm could produce a satisfying effect with distinguishing C-line selleck chemical and T-line from the background. Figure 7 Images of test strip. (a) Original test strip image.(b) Test strip image with traditional HE. (c) Test strip image with WTHE. (d) Test strip image with proposed algorithm. During processing, we set v = 0.1 and r = 0.4, with the least mean square error (MSE). After image processing, the distinct graph of T-line and C-line is displayed in Figure 8 to certify the effectiveness of this algorithm. Figure 8 Curve figure of the test strip image after processing of the proposed modified WTHE algorithm. Diagnosis of CagA samples In order to test the device, 50 positive and 50 negative CagA samples from a clinical hospital were collected for detection. The outcomes showed that the instrument could realize detection with a specificity of 98% and a selleck kinase inhibitor sensitivity of 96%. The specificity and sensitivity are calculated according Sitaxentan to the following equations, respectively: Compared with naked eye detection, the device could recognize low-concentration samples by employing the proposed
image processing algorithm, thus greatly enhancing sensitivity. Additionally, in order to improve specificity, more samples could be detected to set a more exact threshold. To eliminate the error introduced by the differences between test strips and samples, we used HCG samples to set a threshold of T/C ratio to determine the specification. The more antigen targeting in the sample, the more QD conjugates would be captured on the test line, which leads to the increase of the T/C ratio. According to the principle described above, the T/C ratio would be proportional to the concentration of CagA in the samples. Compared to the bare detection of the test line, this quantitative approach is much more credible and applicable. Besides, seven CagA samples with different concentration were also prepared by our group.