Luchetti et al.Monoclonal antibodies conjugated with superparamagnetic iron oxide particles allow magnetic resonance imaging detection of lymphocytes in the mouse brain. Mol Imaging. 2012 Apr 1;11(2):114-25.
These researchers labelled cells with antibodies attached to superparamagnetic iron oxide (SPIO) particles as cellular specific magnetic resonance contrast agents to image lymphocyte or white blood cell populations within the central nervous system (CNS).
The goal of this research is to find a reliable tool for noninvasively detecting and tracking specific cellular populations in humans.
The superparamagnetic iron oxide (SPIO) particles is the contrast agent, by means of its T2* MRI relaxation properties; the antibody is the targeting vector, responsible for homing the particle to target a surface antigen on a cell.
You must remember that the immune system makes antibodies to bind selectively to a specific target; we can then use these antibodies for doing research like this.
To investigate the efficiency of particle vectorialization by these antibodies, they compared two types of antibody-vectorialized CD3-specific particles in vivo (CD3 is a marker for T-cells). They also successfully employed vectorialized SPIO particles to image B220+ cells in a mouse model of B-cell lymphoma (cancer of lymphoid cells). Likewise, they were able to identify CD3+ infiltrates in a mouse model of MS. The specificity of the technique was confirmed by histology and electron microscopy.