Histopathologic and Cytogenetic Techniques Dehydration, Clearing & Decalcification

University:
Princeton University
Course:
PHY 103 | General Physics I
Academic year:

2023
Views:

0

Pages:

2
Author:

beau riego

HISTOPATHOLOGIC AND CYTOGENETIC TECHNIQUES DEHYDRATION, CLEARING & DECALCIFICATION Introduction Histopathology is the branch of pathology that involves the microscopic examination of tissue in order to study the manifestations of disease. It is a crucial field in medical diagnostics, aiding in the identification of various conditions including infections, inflammatory diseases, and cancers. The examination of tissues requires several preparatory steps to ensure accurate analysis, including fixation, dehydration, clearing, embedding, sectioning, staining, and microscopic examination. Decalcification ● Methods of Decalcification ● Methods of Testing for the Completeness of Decalcification ● Post Decalcification Dehydration ● Dehydrating Agents Dealcoholization / Clearing ● Clearing Agents Dehydration is defined as a process in which water is entirely removed from the tissues. It prepares the tissue to be enveloped in a medium (paraffin wax) which is not miscible in water. Clearing, which is also known as dealcoholization, follows after dehydration. In clearing, alcohol is replaced by a solution (clearing agent) which is more miscible with paraffin wax. At the same time, alcohol renders the tissues “optically clear.” The commonly used reagents in this step make the tissues transparent due to their relatively high refractive index, hence the term "clearing." Not a routine step in tissue processing is decalcification. Bone decalcification is the removal of calcium ions, a necessary step in processing hard tissues such as bones and teeth. The process involves the use of acidic or chelating agents to dissolve calcium deposits, allowing tissues to be sectioned and examined effectively. Without decalcification, cutting through mineralized tissues would be difficult and could damage both the sample and the equipment. Histopathological examination includes several key techniques, including special stains, immunohistochemistry, and molecular pathology. Special stains, such as PAS and Masson's trichrome, help identify specific tissue components. Immunohistochemistry utilizes antibodies to detect proteins within tissues, aiding in the classification of tumors and identification of infectious agents. Molecular pathology involves techniques such as polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) to analyze genetic material within cells. Histopathologists play a vital role in diagnosing diseases by interpreting microscopic images and correlating findings with clinical data. Proper tissue preparation, precise staining techniques, and thorough microscopic analysis are essential in producing accurate and reliable histopathological reports. Advances in digital pathology and artificial intelligence are transforming the field, allowing for enhanced diagnostic capabilities and remote consultations. These technological developments are improving efficiency, accuracy, and accessibility in histopathology. Overall, histopathology remains a cornerstone of modern medicine, providing invaluable insights into disease processes and guiding clinical decision-making. It requires meticulous attention to detail, specialized expertise, and continuous advancements in technology to ensure high standards in medical diagnostics.