Punch your own holes to make tissue chips, how to choose the aperture and arrangement of the donor wax blocks?

60 cases, 2 points per case, I will prefer 1.5mm. Although 1.0mm can be multiple rows of points, it requires high texture for paraffin blocks, and is prone to cracking or missing cores, especially when the archived wax blocks become brittle over time. 1.5mm is better in representativeness and section integrity, and is more friendly to subsequent IHC interpretation. If you are worried about tissue volume, you can first mark the tumor area with HE markers and then puncture it to ensure that it is taken to the area with high tumor content. If the budget sample is sufficient, a pre-test wax block can be used first, and 10 cases can be tested with 1.0 and 1.5 mm, respectively, to see the integrity rate and staining heterogeneity before being determined.

The slice thickness is generally 4-5μm, which is too thin and easy to roll and drop. Fish slices at a water bath temperature of 42-45°C, coated with cationic slides or polylysine. Bake the patch at 60°C for more than 2 hours after patching or overnight at 37°C, followed by another 15-30 minutes at 60°C before dewaxing. If there is a crack in the slice, lightly apply the wax block surface with a warm wet towel before cutting, or use a glycerol-containing water bath display. Every 10-20 sheets are sampled under a microscope to check the HE to see the organizational integrity and representativeness, so as to avoid finding the drop point at the end.

Before using the perforating needle, soften the donor wax block on warm water at 37-40 °C or on the hot table for 5-10 minutes, feed the needle vertically, rotate it evenly, and remove it to avoid violence. The HE tablets were taken before each case to avoid necrosis, hemorrhage, and large fibrosis, and tumor cell densities were preferred. The receptor wax block can be placed at room temperature after perforation, but it is best to rewarm before slicing to reduce cracks. When cutting, use a sharp blade and change the blade every 20-50, slowly and uniformly.

It is recommended not to get too close to each other at 2 points in each case. A normal tumor or two different tumor areas can be staggered to increase representation. When arranging, leave the first row or the last row as the anchor point, and use tissues with high recognition such as normal liver, kidney, or placenta to make asymmetric marks; you can also empty a row or empty holes for directional instructions. The point spacing is recommended to be 0.5-1mm, do not be too tight, leave the edge 2-3mm blank to prevent the edge from collapsing when slicing. Draw a dot matrix diagram and then drill holes, and record the corresponding sample number for each hole.