Are all cells recovered from MACS® Columns?
Unlabeled cells can directly be taken from the column effluent. Magnetically labeled cells can be eluted from the columns for positive selection by firmly pushing the plunger into the column outside the magnet. When using an autoMACS™ Separator, the elution step is part of the autoMACS program. Magnetically labeled cells are eluted at outlet port pos1 or pos2, dependent on the program chosen for positive separation, while unlabeled cells are collected at outlet port neg1.
Does the separation of cells over a MACS® Column influence the viability of the cells?
Cells separated with MACS® Technology over a MACS® Column show an excellent viability.
Which MACS® Column is used for which application?
The choice for a special separation column depends on the following parameters:
- separation strategy: (positive selection or depletion)
- number of cells in the sample (number of total cells and number of magnetically labeled cells).
Columns for positive selection:
Cells labeled with MACS® MicroBeads can be positively selected using MS, LS, or XS Columns. Positive selection can also be performed using autoMACS™ Columns and an autoMACS™ Separator.
Columns for depletion:
The depletion efficiency greatly depends on the strength of the magnetic labeling. Cells with strong magnetic labeling can be efficiently retained in MS Columns, LS Columns, or XS Columns. LD Columns, CS Columns, or D Columns efficiently retain weakly as well as strongly labeled cells. Therefore, highest purities of cell depleted fractions will be obtained with the latter column types.
Depletions can also be performed using autoMACS™ Columns and an autoMACS™ Separator with the appropriate depletion program.
For further information see also the Column Decision Flyer.
Recommendations regarding column types and autoMACS programs are given in the MACS® Cell Separation Reagent data sheets.
Which MACS Columns are recommended for the isolation of untouched cells with MACS® Cell Isolation Kits?
MS Columns, LS Columns, or XS Columns are recommended for most MACS® Cell Isolation Kits to isolate untouched cells by depletion of non-target cells.
A number of MACS® Cell Isolation Kits for the separation of cell subsets are based on a multi-parameter sorting: depletion (first separation step) is followed by positive selection (second separation step), and LD Columns are recommended for the depletion step. It is important to follow the detailed recommendations given in the MACS® Cell Separation Reagent data sheets.
What is the difference between LS Columns and LD Columns?
LS Columns are used for positive selection. They can also be used for depletion, provided the magnetic labeling is strong enough.
LD Columns are recommended for depletion. The unique specifications of LD Columns, given by specific shape and matrix, result in a slower flow rate, as compared with the flow rate of LS Columns. Thus, also weakly labeled cells are retained with high efficiency.
LS Columns and LD Columns both fit into the same separators, either directly (MidiMACS™ Separator, QuadroMACS™ Separator) or in combination with column adapters (VarioMACS™ Separator, SuperMACS™ II Separator).
MACS Column names
The column names are product names. The capital letters do not represent particular abbreviations.
Why are MACS® Columns designed as single use items for manual separations, while autoMACS™ Columns can be used several times?
All MACS® Columns are packed in a sterile way. Pure cell populations can be separated under sterile conditions, which is a prerequisite for many downstream applications.
Thus, the single use of MACS® Columns for manual separations results in an optimal equilibration and column performance and avoids undesired contaminations of the cell fractions.
In contrast to MACS® Columns for manual separations, autoMACS™ Columns can be used several times:
Once installed into the autoMACS™ Separator, autoMACS™ Columns have to be permanently stored under liquid. This avoids oxygen-induced detrimental effects on the column matrix. Importantly, autoMACS Columns have to be rinsed and disinfected as recommended. Therefore, an autoMACS washing program is recommended after each separation run. Furthermore, the instrument provides the disinfection program ‘clean’ by which the complete internal system is thoroughly rinsed with ethanol. An overnight storage of the columns is done by selecting the ‘sleep’ program after the last separation of the day. Here again, an ethanol fill allows for leaving autoMACS Columns assembled within the device for a maximum of two weeks or for 100 separations within these two weeks.