Magnetic beads can be used as solid support phase in DNA extraction and purification protocols by a simple bind/wash/elute principle. The products in this category are intended for own development of protocols and are suitable for various sample sources and buffer systems. MagSi-beads for genomic applications are available with a range of physical properties and a silica or carboxyl modified surface.
Carboxylated magnetic silica beads of 1,2 μm size with optimized magnetic content for fast separation and medium suspension time. Intended for nucleic acid isolation from various sources (blood, cells, bacteria etc.) for manual and automated work-flow. Under specific conditions, the carboxylated surface enables higher yield and purity from samples.
Specific Application of Silica- and of Carboxylated Beads
Bead surface | Silica beads | Carboxylated beads |
Compatible Buffer Systems | Chaotropic buffers | PEG-based, low pH or chaotropic buffers |
Binding Mechanism | Precipitation with chaotropic salts | Precipitation by polymers like PEG, divalent cations (e.g. Mg2+) or chaotropic salts |
Elution | Low salt conditions | Low salt conditions or pH shift from acidic to alkalineconditions |
Recommended use | Recommended in case chaotropic conditions can be applied. | Recommended if flexibility in buffer systems is necessary or if non-chaotropic conditions have to be applied. Results in higher purity and recovery rate under non-chaotropic conditions. |
Concentration | 20 ±1 mg/ml |
d50 | 1,1-1,3 µm |
Bead number | 0,6-2 x 1010 beads/ml |
Assay (Iron oxide) | ≥50 % |
DNA yield (20 µl beads) | >3 µg |