Marinho Pedro F, Hanscheid Thomas
Instituto de Microbiologia, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal.
Instituto de Medicina Molecular João Lobo Antunes, Edifício Egas Moniz, Avenida Professor Egas Moniz, 1649-028 Lisboa, Portugal.
MethodsX. 2023 Feb 12;10:102079. doi: 10.1016/j.mex.2023.102079. eCollection 2023.
Histopathology is the study of how disease alters human and animal tissue and is based on the microscopic examination of stained tissue sections. To maintain tissue integrity, preserving it from degradation, it is initially fixed, primarily with formalin, before being treated with alcohol and organic solvents, allowing the infiltration of paraffin wax. The tissue can then be embedded in a mold and sectioned, usually at a thickness between 3 and 5 μm, before staining with dyes or antibodies to demonstrate specific components. As the paraffin wax is insoluble in water, it is necessary to remove it from the tissue section before applying any aqueous or water-based dye solution, to allow the tissue to successfully interact with the stain. This deparaffinization/hydration step is normally carried out using xylene, an organic solvent, followed by hydration using graded alcohols. However, this use of xylene has been shown to have detrimental effects on acid-fast stains (AFS), such as those employed to demonstrate , including the causative agent of tuberculosis (TB), as the integrity of the lipid-rich wall present in these bacteria may be compromised using xylene. A simple, novel method, Projected Hot Air Deparaffinization (PHAD) removes the solid paraffin from the tissue section without the use of any solvents, which produces significantly improved staining results using AFS. PHAD relies on the projection of hot air onto the histological section to melt and remove paraffin from the tissue, which can be achieved using a common hairdryer. •PHAD relies on the projection of hot air onto the histological section which can be achieved using a common hairdryer.•The blowing force is such that melted paraffin is removed from the tissue in 20 min.•Subsequent hydration allows for using aqueous histological stains with success, such as the fluorescent auramine O acid-fast-stain.
组织病理学是研究疾病如何改变人类和动物组织的学科，它基于对染色组织切片的显微镜检查。为保持组织完整性，防止其降解，组织最初会用福尔马林进行固定，之后再用酒精和有机溶剂处理，以便石蜡能够渗入。然后，组织可被嵌入模具并切片，切片厚度通常在3至5微米之间，之后用染料或抗体染色以显示特定成分。由于石蜡不溶于水，在应用任何水性或水基染料溶液之前，有必要从组织切片中去除石蜡，以使组织能够成功与染色剂相互作用。这种脱石蜡/水化步骤通常使用有机溶剂二甲苯进行，随后用梯度酒精进行水化。然而，已证明使用二甲苯会对抗酸染色（AFS）产生不利影响，例如用于显示包括结核分枝杆菌（TB）病原体在内的染色，因为使用二甲苯可能会破坏这些细菌中富含脂质的细胞壁的完整性。一种简单的新方法，即投射热风脱石蜡法（PHAD），无需使用任何溶剂即可从组织切片中去除固体石蜡，使用抗酸染色时能显著改善染色结果。PHAD依靠将热风投射到组织学切片上以熔化并从组织中去除石蜡，这可以使用普通吹风机来实现。•PHAD依靠将热风投射到组织学切片上，这可以使用普通吹风机来实现。•吹风力使得熔化的石蜡在20分钟内从组织中去除。•随后的水化使得能够成功使用水性组织学染色剂，例如荧光金胺O抗酸染色剂。
