Fractionation is performed by introducing a dense sucrose or other chase solution into the bottom of a centrifuged tube, thereby raising the gradient intact by bulk flow. Chase solution is injected either by piercing the bottom of the tube with a short needle, or through a needle from the top.
Used with the Brandel Syringe Pump or our single-channel Peristaltic Pump, the tube holder and piercing mechanism provides bulk displacement fractionation at an economical price.
For on-line absorbance monitoring, the fractionator is used with an absorbance detector and density gradient flow cell.
To fractionate without scanning, you can use a universal top-holder in place of the flow cell to channel the gradient through narrow-bore tubing to the fraction collector or detector.
Brandel, Inc. (Biomedical Research & Development Labs, Inc.), 8561 Atlas Drive, Gaithersburg, MD 20877-4135. Tel: 800-948-6506; Fax: 301-869-5570.