Magnetic bead extraction and centrifugal column extraction are two common nucleic acid extraction techniques, each with its own advantages and disadvantages, suitable for different experimental needs. The following is a comparison:

Technical Principles:

• Magnetic Bead Extraction: Relies on the binding of nucleic acids to surface-modified magnetic particles (e.g., carboxyl groups, silanol groups). Impurities are separated by a magnetic field, and nucleic acids are released through elution. The core is the chemical modification of magnetic beads and the manipulation of the magnetic field.
• Centrifugal Column Extraction: Based on the specific adsorption of nucleic acids by a silica membrane in a high-salt environment, impurities are separated by centrifugal force, and elution is achieved with a low-salt buffer. The core is silica membrane adsorption and salt concentration gradient control.

Operational Procedures:

• Magnetic Bead Extraction: Simplified procedures, suitable for automation (e.g., 96-well plate processing), pretreatment time reduced by 30%. Requires a magnetic rack or automated equipment.
• Centrifugal Column Extraction: Requires multiple centrifugations and solution changes; manual operation is more common, suitable for small to medium throughput experiments.

Purity and Yield:

• Complex Samples: Magnetic bead extraction is more tolerant to inhibitors such as heme and heparin, increasing purity by 15%-20%. Micro-nucleic acid: Centrifuge column method has a higher recovery rate (10%-12% higher than magnetic bead method), suitable for low-concentration samples (e.g., cfDNA).

Long fragment retention:

• Magnetic bead method has gentler elution conditions, which is beneficial for the integrity of DNA fragments >20kb.

Cost and environmental impact:

• Single-use cost: Centrifuge column method has 25% lower consumable costs, but magnetic bead method can reduce long-term costs by reusing magnetic beads (3-5 times).

Applicable scenarios:

• Magnetic bead method preferred: High-throughput detection, automated platforms, complex samples (e.g., blood, environmental samples).
• Centrifuge column method preferred: Small-scale studies, limited budgets, focusing on long fragment extraction (e.g., genome sequencing).