The video demonstrates a paper-based immunoassay, involving amine-functionalized cellulose discs cross-linked with glutaraldehyde. Covalent immobilization of IgG-Fc-specific capture antibodies, followed by the introduction of immunoglobulin G and horseradish peroxidase-conjugated detection antibodies, results in a color change confirming the presence of immunoglobulin G.
Protocol
1. Grafting Amine Functional Groups on Cellulose Paper Discs Prepare one piece of square paper with a dimension of 1 cm × 1 cm, and 100 paper discs made from grade No. 1 cellulose paper with a diameter of 6.0 mm (medium-flow filter paper) using a hole punch. To derive -NH2 groups on the paper discs, mix 1 ml 3-aminopropyltrimethoxysilane (APS) and 10 ml acetone in a 50 ml glass bottle in the fume hood. Add paper discs to the freshly prepared APS reagent mixture,…
Representative Results
Figure 1. Fourier transform infrared (FTIR) spectra of untreated and APS-treated medium-flow filter square paper (A) and fast-flow filter square paper (B). A. The spectra for untreated medium-flow filter square paper was similar to that of APS treated medium-flow filter square paper. The increase in intensities at bands of 902-1,170 cm-1 …
PBS, containing 137 mmol/L NaCl, 2.7 mmol/L KCl, 8.0 mmol/L Na2HPO4 and 1.5 mmol/L KH2PO4, is prepared with water and adjusted to pH 7.4 with 0.1 mol/L NaOH or 0.1 mol/L HCl