Occasionally, researchers need very large numbers of purified cells which means that sorting for purity with flow cytometry is impractical because it would take too long. To accommodate these people, the RRC purchased a Miltenyi-Biotec automatic magnetic bead cell separator (AutoMACS), which can sort millions of cells in minutes. This instrument was installed in December of 1999 and has been used often as a presorter for very rare cell populations. In this instance, the few desired cells were first separated from the millions of unwanted cells with the AutoMACS, and then sorted by flow cytometry in order achieve high purity. The AutoMACS is also very useful in instances where time is of essence and extremely high purity is not an issue. This instrument makes the cell purification with magnetic beads simple and fast. Manual magnetic bead separations take up to two or four times longer than using this instrument and pressure / flow rates on manual separation columns are hard to control. The drawbacks for this instrument are 1. it can only be used for markers that are on the cell surface (intracellular markers such a GFP would have be purified with flow cytometry) and 2. the purity is not as good (75%-95% purity) when compared with flow cytometry sorting (97%-99% purity). Purity is compromised when using the AutoMACS positive selection mode because your desired cells will be contaminated with dead cells. The depletion mode on the AutoMACS will generate cell preparations of greater purity but you would need to have beads that will react with all of your unwanted cells. For more information on the AutoMACS, contact the University of Chicago web page at: http://iacf.bsd.uchicago.edu/FlowHome/InstrumentPics/Automacs.htm

At present there is no instrument charge for the use of this instrument. Only the cost of materials (columns and buffers) is charged to the investigator.