A perimeter clip is made of a single piece of sheet metal and includes first and second legs that are bent at approximately 90 degrees with respect to each other. To counter this, the invention provides a novel bioprocess where aggregation of spheroid forming cells, such as embryonic stem cells and spheroids, such as EBs is controlled, such as by encapsulation of within a matrix. The first part is a non-elastomeric ring, and the second part has an elastomeric ring having opposite axial ends, one of which telescopically fits to the non-elastomeric ring of the first part and the other of which joins with a second non-elastomeric ring. The image-reading device further includes a pre-charge transistor, an amplification transistor, a readout transistor, a compensation transistor, and a power-source switching transistor. In one embodiment, the about 90\xb0 has a tolerance of \xb130\xb0. The cooling circuit is disposed on an opposite inside surface defining the tube, wherein the cooling circuit shields the gradient coil from the RF coil while cooling the gradient coil.