Embedding Well Bars
Embedding is performed in wells machined into the face of one-inch thick stainless steel bars. Well bars are available in 10 mm, 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.
Over-chuck freezing blocks
These steel rectangular blocks are a tool useful for a number of tasks. They serve as a heat extractor, designed to fit over the stem of the chuck .The flat surfaces can also be used as an extra heat extractor when using conventional cryostat embedding technique. The freezing block also served as a dislodging tool. A light tap of the chuck stem cleaves the plane of adhesion holding of the formed block to the well. These blocks also serve as a convenient hand held flat freezing surface useful in gently cooling the tissue without the use of sprays and in plastering technique discussed below.
These thin transparent vinyl slides serve as a surface to precisely orient the tissue into the desired position and as a means to accurately transfer tissue to the embedding well floor. Tissue is applied face down to the end of the transparent slide where it can be visualized from below and manipulated into position. The face that is visible will be laid onto the well floor and will ultimately be the embedded surface to be sectioned.
This removable shelf can be installed below the opening of the cryostat in the most convenient and ergonomically comfortable location available. The shelves can be made in various sizes to accommodate most instruments. If the user chooses not to install a shelf, or if the cryostat does not accommodate a shelf, the embedding well bars can be placed on the brush holder in many cryostats. Bars can be stacked to increase elevation.
Cutting board /Freezing griddle(right)
The steel “Freezing Griddle” serves as a freezing surface on which to prepare frozen blocks when used in conjunction with the elevated freezing block. The small attached cutting board serves as a cold surface to cut the frozen block while maintaining the freezing temperature. This simple piece of apparatus is kept cold in the cryostat and is removed to the work bench only during the process of cutting the frozen block. As sections are cut, they are kept cold on the freezing griddle.
Elevated Freezing Block (left)
This steel block is kept cold in the cryostat and is used in conjunction with the freezing griddle. The two broad sides of the block are equipped with feet measuring 3.0 mm on one side and 4.5mm on the other. The feet create a space between the two steel bars in which the frozen blocks are prepared. Additional elevating bars are supplied to further elevate the block when preparing very thick portions of tissue.