Cryo gel embedding medium

Fresh samples of normal renal cortex were obtained within 2 hours after surgery from a 46-year-old male who had a total kidney resection due to a renal malignancy. Samples were snap frozen using either Cryo-Gel embedding medium (Leica, Surgipath, the Netherlands), Tissue-Tek OCT Compound (Sakura Finetek, the Netherlands) or no embedding compound. The quality of tissue histology, EM, DNA, RNA and proteins was evaluated (Fig. 1). In addition, fresh samples from normal spleen, skin, liver and colon from surgical resections due to malignancies were collected. These tissues were snap frozen using Cryo-Gel, OCT and no compound. The quality of tissue histology, DNA, RNA and proteins was evaluated in these tissues. For each medium two samples were embedded. For renal tissues, the experiments were performed in duplicate. In addition, a section of a renal biopsy from a patient with known lupus nephritis was used to evaluate the quality of IF on Cryo-Gel embedded tissue.

After methanol fixation tendons were decalcified using 10 % EDTA solution (HNaO Sodium hydroxide S5881 Sigma, Germany; EDTA A3234 AppliChem, Germany) for three to six weeks under control by X-ray (30 kV and 10 s; X-ray equipment: Cabinet x-ray systems faxitron series, HP, Germany and X-ray film: Structurix D4DW 18 × 24, NDT Systems, Agfa, Germany). Then tendons were transferred to 100 % methanol. Twenty-four hours prior to cryosectioning, tissue samples were stored in a 5 % sucrose and phosphate-buffered saline solution. Sections were sliced to thickness of twelve micrometers (Cryostat CM 1950, Leica, Germany and Cryo Gel Embedding Medium, Leica, Germany). Hematoxylin and eosin staining was performed. On the basis of a semi-quantitative four-point-scoring system (from 0 = normal to 3 = markedly abnormal appearance) in six categories: (1) fibre arrangement, (2) tendon fibre structure, (3) regional variations in cellularity, (4) increased vascularity and (5) scarring (decreased collagen staining) and (6) hyalinisation were assessed as established by Longo et al [17 (link)]. The final score results from the sum of the individual scores given in each category.