Accurate and reproducible biomolecule labeling is a cornerstone of modern life science research, supporting the detailed study of cellular pathways and the creation of advanced diagnostics and therapeutics. Traditional labeling methods often depended on non-specific reactions, producing heterogeneous outcomes with inconsistent labeling and unpredictable effects on biomolecule function. Today, the field is undergoing a paradigm shift fueled by next-generation labeling chemistries—such as click chemistry, site-specific conjugation, and bioorthogonal labeling—that deliver unmatched precision and consistency.