Cell Culture Washes and Dilutions: Isotonic rinses that preserve membrane integrity; Mg2+ supports cell adhesion and morphology.

Immunocytochemistry/Immunofluorescence Wash Buffer: Maintains epitope stability and Mg2+-dependent cell-surface interactions during staining.

Flow Cytometry Staining Buffer: Provides physiological ions; Mg2+ and K+ help maintain receptor conformation and reduce cell stress during labeling.

Receptor–Ligand and Integrin Adhesion Assays: Supports divalent cation–dependent binding events requiring Mg2+ for optimal affinity.

Phage Adsorption and Plaque Assays: Enhances bacteriophage infection efficiency of hosts like E. coli through Mg2+-dependent adsorption.

Bacterial Wash/Resuspension: Stabilizes outer membranes of Gram-negative bacteria (e.g., E. coli, Salmonella) via Mg2+–LPS interactions.

Nuclease Reactions (e.g., DNase I): Supplies Mg2+ cofactor while phosphate buffer maintains pH for controlled nucleic acid digestion.

Protein–Protein Interaction Assays: Preserves physiological ionic strength with K+ and supplies Mg2+ for cation-dependent complexes.

Magnetic Bead–Based Cell Separation: Maintains divalent cation conditions that support cell viability and surface marker integrity.

General Reagent/Sample Preparation: Diluent for magnesium-dependent workflows where phosphate buffering is preferred.