Loading Controls are antibodies that recognize stably expressed housekeeping proteins. They are used to correct for sample loading errors, assess membrane transfer efficiency, and monitor sample quality, thereby ensuring the reliability and comparability of results in Western Blot, immunofluorescence and other immunoassays. Selection of appropriate loading controls is based on subcellular localization and sufficient molecular weight difference from the target protein, with common references including β-actin, GAPDH, Tubulin, Lamin B1, Histone H3, COX IV, Na+/K+-ATPase and Vinculin. It is important to confirm stable expression under experimental conditions, avoid molecular weight overlap, and optimize antibody concentrations to prevent signal saturation.