Polymerase Chain Reaction (PCR/qPCR/RT-PCR): Supplies Mg2+ cofactor to optimize DNA polymerase activity, specificity, and yield in amplification reactions.

Sanger Sequencing and DNA Extension: Adjusts Mg2+ concentration to control polymerase kinetics and improve read quality and accuracy.

Restriction Enzyme Digests: Provides essential Mg2+ for many restriction endonucleases to achieve complete and specific DNA cleavage.

Ligation and DNA End Modification: Supports Mg2+-dependent enzymes (e.g., ligases, kinases, phosphatases, terminal transferases) for efficient DNA/RNA end processing.

In Vitro Transcription/Translation: Supplies Mg2+ required for T7/T3/SP6 RNA polymerases and ribosomal function in cell-free protein expression.

Nuclease Assays: Enables activity of Mg2+-dependent nucleases such as DNase I, RNase H, and CRISPR-Cas enzymes.

Preparation of Chemically Competent Escherichia coli: Included in transformation buffers to enhance plasmid DNA uptake during heat-shock transformation.

Buffer and Media Supplementation: Tunes Mg2+ levels in molecular biology buffers and minimal media to stabilize nucleic acids and support enzyme activity.