Processing method and cassette

A method of avoiding deformation of a biological tissue sample during preparation for analysis comprising:

• i) providing a histology processing cassette comprising a box defining a compartment for holding a biological tissue sample, the box having a bottom face comprising a sample support surface and being transmissible to radiation or a flow of fluid through the face, an open top face, and two side walls, a back wall and a front wall, the box having a length of 65 to 80 mm and width of 50 to 55 mm, being a greater length and width than a standard size histology processing cassette and a depth of 6 to 8 mm being approximately the same as a standard size histology processing cassette, wherein the ratio of the length to the width is approximately from 7 to 8:5, the ratio of the width to the depth is from 6 to 9:1, and the ratio of the length to the depth is from approximately 9 to 12:1, whereby the compartment is adapted to reduce curl of said biological tissue sample in the same dimension as the depth of the compartment;
• ii) placing the sample in the cassette and treating the sample by contacting it with a processing solution;
• and
• iii) contacting the sample with molten paraffin and cooling the sample in molten paraffin so the sample is embedded in solidified paraffin for further processing.