Photo: the use of colored-agar markers within
the clear agar block as orientation markers.

Here is another excellent refinement. We use small India-ink-impregnated black agar markers to indicate two orientations: (1) small black triangle or block says "begin here" when cores are pre-embedded in a series of 2 or 3, such as "A-C" [the 3 from the right half of the prostate] or "D-F" [3 from the left]. (2) a narrow black bar is situated at right angles to the triangular/block marker and is the boundary toward which one situates the core ends representing the biopty-gun needle tip end (the end at the "tip"/head of the "blot

paper" arrow mark). All elements (cores and markers) are clear-agar pre-embedded and thereby incorporated into a block.