Fractionation of blood components using high gradient magnetic separation

We review a wide range of strategies for using high gradient magnetic separtion to fractionate blood components. The physics bases of the techniques involve: (i) variations in cell haemoglobin and cell geometry; (ii) changes in haemoglobin magnetic susceptibility in various carrier environments; (iii) the use of paramagnetic carrier fluids. Single wire and bulk filter studies are reported which show that these techniques can be successfully applied to: (a) white cell and platelet counting; (b) cell fractionation on haemoglobin type and content; (c) diamagnetic white cell and platelet separation; (d) nucleated red cell studies; (e) sickle cell separation. We show that red blood cells can be magnetically separated both paramagnetically and diamagnetically and offer a basis or the assessment of diamagnetic capture efficiency.