Sample Fractionation Using Magnetic Beads

To find protein and peptide biomarkers in a biological sample, fractionation is usually required to reduce dynamic range and sample complexity. LC is a standard way of fractionating samples. Although it has a great resolving power, it is time consuming and is less ideal for the processing of many samples in parallel. Magnetic beads (Dynabeads) offer the opportunity of manual or automated high-throughput fractionation upstream of MS or 2D-gels. With 96-384 wells available, many samples can be run in parallel with one or several different chromatography surfaces (e.g., SAX, SCX and RPC 18). Because of high sensitivity and reproducibility, Dynabeads have become a popular choice for serum peptide profiling and for the pre-selection of samples (e.g., upstream of LC-MS).