Embedding Well Bars
Embedding is performed in wells machined into the face of one-inch thick stainless steel bars. Well bars are available in 18 mm. 24 mm. and 30 mm. and 50 x 30 mm width across the base. (A bar machined with both 30 and 24 mm. wells is not shown). These bars are stored in the cryostat and serve as a powerful heat sink to rapidly freeze the block.
These stainless steel chucks are designed to be used cold for rapid freezing, and to maximize the gripping power required to hold the embedded tissue block. Chucks can also be used warm with use of the “over-chuck freezing blocks”. The stem of the chuck provides the focal point for a sharp tap resulting in an easily release of the block from the well. These chucks fit many of the major brand cryostat and can be used in most cryostats with use of an adaptor.
A) Place tissue on a thin film of embedding medium face down on the dispensing slide and place the tissue on the freezing griddle.
B) Cover the tissue with an ample quantity of embedding medium.
C) Place the elevated freezing block over the tissue. Freezing time is about one minute.
D) Remove elevated freezing block with a twist. The lines show the cuts to be made in numerical order.
E) Remove the cutting board to the workbench. Test the frozen block for hardness while trimming the edges of the frozen medium. The block should cut like hard ice cream.
F) If there is any tendency for the cut piece to fly apart it is too hard. Warm the frozen block for a few seconds between the gloved hands and retest.