The conjugation of oligosaccharides with proteins, peptides, and other molecules generates a wide array of valuable tools for biochemical and biomedical research. However, conjugation methods often suffer from low efficiency, particularly when working with limited quantities of oligosaccharides. In this study, we report the conjugation of a synthetic oligosaccharide analog of the glycotope αGal (α-d-Galp-(1 → 3)-β-d-Galp-(1 → 4)-d-GlcNAc) with bovine serum albumin (BSA) using the squaric acid method. The protocol is versatile and can be applied to conjugate any oligosaccharide with proteins or peptides. A notable advantage of this method is its efficiency in using minimal amounts of the reactants while allowing the progress of the conjugation to be monitored via thin-layer chromatography, eliminating the need for complex instrumental techniques.