Figure 12.

Vogel technique to construct evenly long PTCBs. (A) A so-called cutting board is a 4 mm thick plate made of e.g., polymethylmethacrylate (plexiglas^®) with numerous holes to accommodate PTCBs. The PTCBs can be installed into the plate with a paraffin tissue punch. (B) The holes of the cutting board can be filled with as many PTCBs as necessary to achieve a length of 4 mm. The part of the PTCB which surmounts the surface of the cutting board can be easily cut with a used microtome knife and inserted into another hole to spare the sometimes precious tissue. (C) The composite PTCB (arrows) can be retrieved from the cutting board with the stylet of the paraffin tissue punch. (D) The PTCBs punched out of the donor paraffin blocks are of different length (bottom). After the installment into the cutting board the composite PTCBs are of equals length (top). (E) A 4 mm long composite PTCB composed of several very short PTCBs. (F) The composite PTCBs (arrow) can be transferred into the holes of the recipient blocks separately. (G) A tissue arrayer can also be used to transfer all of the composite cores (arrow) of the cutting board (c) into the holes of the recipient block simultaneously (p plastic cassette of the recipient block. (H) A PTMA filled with composite PTCBs by the tissue arrayer. (I) PTCB library in an Eppendorf vial as already proposed by Wan et al. (J) A commercially available paraffin tissue punch (Beecher Instruments, Inc.) was modified with a countersink to facilitate the installment of stored PTCBs into a punch. (K) The cutting board can also be used in combination with a tissue arrayer (e.g., the Beecher tissue arrayer).