Low cfDNA Recovery from Inadequate Bead Dispensing (Cell-free DNA Extraction)

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Accepted Answer

DNA yield is consistently lower than expected across multiple extractions. The binding capacity appears reduced, with proportionally less DNA recovered relative to input sample volume. Common causes: 1) Monarch Mag Beads M2 solution not thoroughly mixed before pipetting, resulting in settled beads 2) Fewer beads dispensed than required due to rapid bead settling during multi-sample processing 3) Beads adhering to pipette tip walls when using standard retention tips 4) Loss of beads in dead volume of pipette tips Solutions: 1) Thoroughly vortex or invert Monarch Mag Beads M2 immediately before each aliquot addition 2) Mix beads frequently during multi-sample dispensing to prevent settling 3) Use low-retention pipette tips to minimize bead loss on tip walls 4) Pipette beads slowly to ensure accurate volume transfer and minimize tip adhesion