Anti fam

The LFB platform was prepared according to a previous report (Cheng et al., 2019 (link)). Briefly, the LFB contained four components: an absorbent pad, NC membrane, sample pad, and conjugate pad (Jie-Yi Biotechnology. Co., Ltd.). The components were assembled orderly on a backing card. The capture reagents, including anti-FAM, anti-Dig, and biotin-BSA (Abcam. Co., Ltd.), were immobilized by physical adsorption on the reaction regions. Then, anti-FAM was immobilized at test line 1 (TL1) (RdRp), and anti-Dig was immobilized at test line 2 (TL2) (N), while biotin-BSA was immobilized at the control line (CL); each line was separated by 5 mm. SA-PNPs (dye streptavidin-coated polymer nanoparticles) were gathered on the conjugate pad. The prepared biosensors were preserved in a plastic box with a desiccant gel at room temperature before use.

We obtained AuNPs-based LFB materials, including biotinylated bovine serum albumin (biotin-BSA; 4 mg/mL), a rabbit anti-fluorescein antibody (anti-FAM; 0.2 mg/mL), and a sheep anti-digoxigenin antibody (anti-Dig; 0.25 mg/mL) from Abcam Co., Ltd. (Shanghai, China), and crimson red dye streptavidin-coated AuNPs (SA-AuNPs; 40 ± 5 nm, 10 mg/mL, 100 mM borate [pH 8.5] with 0.1% BSA, 0.05% Tween 20, and 10 mM ethylenediaminetetraacetic acid) from Bangs Laboratories Inc. (Fishers, IN, USA). Four LFB components (sample, conjugate, absorption pads, and nitrocellulose membranes) were manufactured and laminated on plastic adhesive backing by HuiDeXin Biotech. Co., Ltd. (Tianjin, China) according to our design scheme (Figure 2). Nucleic acid releasers were obtained from BaiAoLaiBo Technique Ltd. (Beijing, China). Universal isothermal amplification kits and the colorimetric indicator, malachite green (MG), were obtained from HuiDeXin Biotech. Co., Ltd. (Tianjin, China). Commercial PCR diagnostic kits for C. trachomatis and N. gonorrhoeae were obtained from DaAn Gene Co., Ltd. (Guangzhou, China).