Small but mighty: How the MACS^®‐technology based on nanosized superparamagnetic particles has helped to analyze the immune system within the last 20 years

Abstract

Today, magnetic cell sorting and flow cytometric cell sorting both are state-of-the-art technologies, with a plethora of applications in biology and biomedicine. Both technologies have their stand-alone applications, but they also perfectly complement each other, in particular for the analysis and isolation of fragile and rare cells. The technological evolution from simple magnets and steel wool separation columns to sophisticated instrumentation and automated procedures has paved the way for magnetic cell separation in the scientific community. This review will focus on applications of magnetic cell sorting with commercially available paramagnetic MACS 1 -nanoparticles (Miltenyi Biotech, Bergisch-Gladbach, Germany) that have allowed unprecedented approaches to the exploration of the immune system in basal and clinical research of humans and rodents. Thus, during the last 20 years this technology has been continuously developed so that the widest array of leukocyte subsets, stem cells, and connective tissue cells can be addressed by MACS 1 -conjugated antibodies directed against cell-specific surface antigens or secreted cytokines for research and clinical applications. ' 2010 International Society for Advancement of Cytometry

Isolating astrocytes and neurons sequentially from postnatal murine brains with a magnetic cell separation technique

“…The advantages of MACS are the high separation capacity [6], the speed of processing, excellent purity and minimal stress to the cells [5]. It is based on high gradient magnetic cell separation with super-paramagnetic microparticles, a concept first described by Molday and Molday in 1984 [7].…”

“…During the last three decades, magnetic cell sorting (MACS) and fluorescence-activated cell sorting (FACS) have been established as state-of-the-art cell isolation technologies [5]. The advantages of MACS are the high separation capacity [6], the speed of processing, excellent purity and minimal stress to the cells [5].…”

“…By placing these columns in a magnetic field, the labeled cells are attracted to the magnet, retained in the columns, and may thus be separated from the unlabeled cells. Elution of the labeled cells is possible after removing the column from the magnetic field [5].…”

Buffer-Optimized High Gradient Magnetic Separation: Target Cell Capture Efficiency is Predicted by Linear Bead-Capture Theory

“…Hence c t , the mean number of beads attached to a target cell, is given by (5) In the linear regime c t is therefore also proportional to n 0 . (6) where (h) is the geometric factor (which is 4/3 for a random filter), F is the filter filling factor (0.12 in our case), L is the filter length (5 cm), M is the saturation magnetization of the matrix material (1.2 MA/m). B 0 is the applied magnetic flux density (0.7 T), η is the fluid dynamic viscosity (2 × 10…”

“…Early work on generic HGMS systems [3,4] eventually led to the development of the MACS HGMS system [5]. Today, the MACS system is still the only viable commercially available HGMS technique in cell biology, with over 12000 studies published during the past two decades [6]. The MACS system relies on HGMS in combination with 20-100 nm diameter paramagnetic beads.…”