Tissue Sampling Guides for Porcine Biomedical Models

Abstract

This article provides guidelines for organ and tissue sampling adapted to porcine animal models in translational medical research. Detailed protocols for the determination of sampling locations and numbers as well as recommendations on the orientation, size, and trimming direction of samples from *50 different porcine organs and tissues are provided in the Supplementary Material. The proposed sampling protocols include the generation of samples suitable for subsequent qualitative and quantitative analyses, including cryohistology, paraffin, and plastic histology; immunohistochemistry; in situ hybridization; electron microscopy; and quantitative stereology as well as molecular analyses of DNA, RNA, proteins, metabolites, and electrolytes. With regard to the planned extent of sampling efforts, time, and personnel expenses, and dependent upon the scheduled analyses, different protocols are provided. These protocols are adjusted for (I) routine screenings, as used in general toxicity studies or in analyses of gene expression patterns or histopathological organ alterations, (II) advanced analyses of single organs/tissues, and (III) large-scale sampling procedures to be applied in biobank projects. Providing a robust reference for studies of porcine models, the described protocols will ensure the efficiency of sampling, the systematic recovery of high-quality samples representing the entire organ or tissue as well as the intra-/interstudy comparability and reproducibility of results.

The Munich MIDY Pig Biobank – A unique resource for studying organ crosstalk in diabetes

“…Body weight and length (tip of nose to base of tail) as well as weights and dimensions of internal organs were determined. To ensure generation of representative, high-quality tissue samples, suitable for a broad range of analyses, standardized sampling procedures [12] were used. From complex organs with several morphologically and/or functionally distinct compartments, such as brain or heart, reproducible samples were taken from standardized, deliberately chosen, anatomic locations in defined orientations.…”

“…From complex organs with several morphologically and/or functionally distinct compartments, such as brain or heart, reproducible samples were taken from standardized, deliberately chosen, anatomic locations in defined orientations. For parenchymatous organs, such as lungs, liver, spleen, kidney, or pancreas, systematic random sampling regimes [12] were employed. Samples taken from the selected locations were fractionated and differentially processed according to the demands of various analytical methods (Table 1).…”

“…[11]). A comprehensive standardized protocol, taking the principles of systematic uniform random sampling into account, was established [12] to ensure uniform high quality of representative samples for a broad spectrum of analyses, including molecular profiling as well as qualitative and quantitative morphological investigations.…”

An Improved Urethral Catheterization in Female Pigs

“…The miniature pig is considered as one of the major animal species used in scientific research and is increasingly being used as an alternative to a dog or monkey as the nonrodent species of choice in the preclinical toxicological testing of pharmaceuticals. [1] Since there are three acute angles bending in the urethra of the male miniature pig, and the end of the penis head is cork-screw shaped, it is difficult to implement routine urethral catheterization in male miniature pigs. Currently, researchers usually implement bladder colostomies or dissections in male miniature pigs, while transurethral urethral catheterization can be implemented in female miniature pigs.…”

Comparative aspects of rodent and nonrodent animal models for mechanistic and translational diabetes research

“…In contrast, mice show the lowest islet volume density in the splenic lobe, although strain differences have been reported [118,119]. Because of the nonhomogenous distribution of endocrine tissue throughout the pancreas, correct determination of fractional volumes of endocrine cells requires systematic random sampling [120] throughout the whole organ. In human studies, the whole organ is not available in many cases; thus, quantitative stereological data from such studies should be interpreted with care.…”