Negative cell separation

Set aside 1 x 106 cell aliquots from the positive and negative cell fractions for FACS analysis. Determine total cell concentration, cell suspension volume, and population viability in the separated cell fractions. 

A typical example of a resonance assisted device might be a cell separator designed to discriminate between cells which have only a small difference in dielectric properties. The cross over frequencies from positive to negative DEP will be similar but not identical for the two cells. By working at a frequency between the two crossovers it is possible to separate the cells but the forces produced will be small unless very high fields are used (Fig. 10). Controlled resonance can be used to boost the fields at the working frequency. 

Stanciu LA, Shute J, Holgate ST, Djukanovic R. Production of IL-8 and IL-4 by positively and negatively selected CD4-I- and CD8-1- human T cells following a four-step cell separation method including magnetic cell sorting (MACS). J Immunol Methods 1996 189 107-115. 

This paper reviews the present status of affinity separation of cells based on the biospecific interaction of cellular receptors with proteinaceous ligands immobilized on a solid-phase matrix. Special emphasis was placed on the development of new matrix materials for immuno-affinity chromatography of lymphocyte subpopulations. Our newly developed matrix of poly(2-hydroxyethyl methacrylate)/polyamine graft copolymer offered novel advantages in (1) elimination of non-specific adsorption of lymphocytes and (2) simple immobilization procedure of ligand protein through non-covalent adsorption. This matrix allowed a rapid separation of preparative quantities of pure and vital lymphocyte subpopulations (IgG-positive and -negative cells) in excellent yield. 

Consider the electrochemical reactor shown in Figure 21.1. The reactor consists of two electrodes immersed in a conducting solution known as an electrolyte. The terminals of the electrodes are connected to an external dc power supply. The positive electrode, anode, and the negative electrode, cathode, are separated from each other by a cell separator thereby dividing the cell into two compartments. The electrolytes in the anode and cathode compartments are known as the anolyte and catholyte, respectively. Two identical reference electrodes are used to measure the individual electrode potentials. When a voltage of sufficient magnitude is applied across the two electrodes, electron transfer occurs between each electrode and its adjacent electrolyte resulting in current flow in the external loop and hence to electron transfer reactions at the electrodes. This phenomenon is known as electrolysis. 

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