Pullulan

PBS buffer, tetramethylbenzidine (TMB), hydrogen peroxide (H₂O₂), pullulan, Tween-20 and bovine serum albumin (BSA) were obtained from Shanghai Sangon Biological Engineering Technology and Services Co., Ltd. (Shanghai, China). Nitrocellulose paper (HF120 and NC0.45 μM) were purchased from GE Healthcare (Chicago, IL, USA). The capture antibody of dAA (cAb, with a concentration of 6 mg/mL) and horseradish peroxidase-labeled acrylamide derivative (HRP-dAA, with a concentration of 2 mg/mL) were supplied by Wuxi Determine Biotechnology Co. Ltd. (Wuxi, China). All other chemicals were obtained from Sigma-Aldrich and used without further purification. Hydrophobic barrier on paper was printed using a Xerox ColorQube 8570N solid wax ink printer (Xerox Corporation, Norwalk, CT, USA).

All DNA oligonucleotides were obtained from Takara Biotechnology Co. (Dalian, China) and purified by standard 10% denaturing (8 M urea) polyacrylamide gel electrophoresis (dPAGE) or high-performance liquid chromatography (HPLC). T4 DNA ligase, dNTP, and T4 polynucleotide kinase (PNK) were purchased from Takara Biotechnology Co. (Dalian, China). ϕ29 DNA polymerase was acquired from Thermo Scientific (Waltham, MA, USA). Pullulan was obtained from Sangon Biotech (Shanghai, China). BCA Protein Assay Kit was acquired from Beyotime Biotechnology (Shanghai, China). Triton X-100 cell lysis buffer SS0890 was obtained from NOVON (Beijing, China). Nitrocellulose paper (HF180), Whatman filter paper 1# and Whatman 3MM CHR chromatography paper were purchased from GE Healthcare (Chicago, IL, USA). All other chemicals were purchased from Sangon Biotech (Shanghai, China) and used without further purification. Water was purified with a Greate Fun SUMMER-S-10 water purification system.
The sequences of the DNA molecules were as follows:
CDT1 (anti-EC1): GATATCATAT CACACAACTG TAAAGAAATC CATCCCCACA CAGTGTAGTG TTCCGGTCGC AGGTCTCGAC AACGCACATC (5′→3′)
TP1: ATATGATATC GATGTGCGTT (5′→3′)
DT1: ACGCACATCG ATATCATATC AC (5′→3′)
CDT2: TAGCTAGGAA GAGTCCCAAC CCGCCCTACC CAAAATGTCT CGGAT (5′→3′)
TP2: TTCCTAGCTA ATCCGAGACA (5′→3′)
F-RS28: ACTCTTCCTA GCFrAQGGTTC GATCAAGA-invert dT (5′→3′)