Cellular pathology: importance of dyes in identifying normal and abnormal histological features of tissues

IntroductionIn the look at of weave papers, histological spying is important in order to study cellular anatomical organizes, intracellular and extracellular substances at the microscopic level (Stevens and Lowe, 1997). patch is an auxiliary technique used in microscopy to enhance contrast in images obtained and to high set down organizes. Stains may be used to define and examine pop out tissues, cell populations or organelles within individual cells histological features useful for biological investigate and/or diagnosis in medicine (Bancroft and Cook, 1994). The importance of dyes in identifying normal and irregular histological features of tissues is herein discussed. Medical and biological explore is underpinned by knowledge of the normal social building and run of cells and tissues as substantiallyhead as the organs and structures they make up (histology) Understanding infirmity in the context of structure-function relationships (histopathology) changes varian tiation between normal tissues and abnormal tissues in a particular disease state (Cook, 2008). The differentiation of these enabled by the identification and sagaciousness of the divergence of normal and abnormal histology is highly beneficial in disease diagnostics and therapeutics (Bancroft and Gamble, 2008). Such essential study disciplines are based on a thorough understanding and ability to recognise basic tissue types which combine to form the different organs of the body. Understanding normal structure of tissues is essential to the identification of altered structure (Lakhani, et al., 1998). With knowledge of normal histology, hotshot can see the types, location and scope of cells involved in disease, whether their native morphology is impacted indicating cellular dysfunction, and whether higher order tissue structure is impaired which indicates organ dysfunction (Stevens and Lowe, 2000).Histopathology, on the otherwise hand, encompasses the means to allege accurate mo dels of particular diseases based on understanding the visual plastic film of molecular mechanisms differentiated from normal (Kiernan, 1999). In the normal healthy state, cells and other elements of tissue are arranged in regular recognisable patterns. Tissues commonly start particular defining characteristics such as surface structure and shapes and formations of constituent cells which are used in their identification and assessment of function (Stevens and Lowe, 1997). Changes in these patterns can be induced by a great range of chemical and physical influences such as microbial infection and cell malignancy in cancer are reflected by geomorphological alterations at the microscopic level (Lakhani, et al., 1998). Many diseases such as pubic louse are also characterised by typical structural and chemical abnormalities which metamorphose the normal pattern of tissues (Lakhani et al., 1998). This is the basis of microscopic examination of specimens. Examination of unhomoge neous specimen and differentiation of structures is challenged as tissue sections or smears obtained from biopsies or aspirations search dull and less exact when viewed in exculpated microscopy. This is because the fixed materials in the preparation have a similar refractive index and have a similar grey colour which makes it difficult to identify the structure of the tissues (Kiernan, 1999). It is essential to stain the cells/tissues to enable better visualisation of the different structures in contrasting colours (Bancroft and Cook, 1994). Staining is most commonly carried out through with(predicate) the use of histological dyes which are coloured organic compounds obtained from natural sources or from synthetic production that selectively bind to or concentrate in various cell and tissue structures (Kiernan, 1999). Dyes contain auxochromes which are chemical components that enable attachment to tissue such as the ionisable OH group, and chromophores which are substances added to absorb unmistakable light responsible for the colour observed. Colour arises when an attached chromophore molecule absorbs received wavelengths of visible light (Bancroft and Gamble, 2008). Most modern dyes such as the Haematoxylin and eosin stains commonly used are synthesised from simpler organic molecules, usually benzene or one of its derivatives (Kiernan, 1999). Stains are generally aimed as special probes, which possess unsettled specificity depending on the unique ionization or chemical reaction with tissue structures and components (Stevens and Lowe, 1997). Staining does not result in a random colour of the tissue specimens, but rather exploits the differences in the chemical structure of the tissue. This is shown by colour variation depending on which dye is bound. Colours acquired reflect the nature of the tissues and their properties and proffers an advantage in the revelation of specific parts or areas (Cook, 2008). This enables expound visualisation of structu res including cell structures such as the cytoplasm, nucleus and organelles, as well as extra-cellular components. Additionally, under certain conditions such as glycogen retentiveness diseases, staining (in this case using the Periodic acid-Schiff (PAS) to detect carbohydrates) can notice molecular compounds and differences associated with pathological conditions (Lakhani, et al., 1998). Enhanced capacity for visualisation and identification of structures is the old advantage for the use of dyes in staining of tissue specimen. Tissue staining therefore plays a scathing role in tissue-based diagnosis and research leaseing the visualization of tissue morphology and histological features, and in distinguishing normal and abnormal histological features (Cook, 2008 Stevens and Lowe, 1997 Kiernan, 1999). These observations are sufficient to allow analysis of tissue health and diagnosis of disease. Histological dyes commonly used for staining in light microscopy include the Haematoxy lin and Eosin stain (H&E), Van Giessen, Massons Trichrome, and Periodic acid-Schiff (PAS), among others. The H&E stain is the most commonly used stain for light microscopy in histology and histopathology. It is routinely used as it provides a very detailed view of the tissue achieved by staining cell structures staining the nuclei a dark blue or purple, and the cytoplasm and connective tissue in shades of pink (Cook, 2008). Staining using these and other dyes forms a critical part of the diagnostic picture given the sufficient contrast obtained for the introduction of tissue morphology (Stevens and Lowe, 1997).In conclusion, staining is an essential process in histology and histopathology with its primary advantage being the enhancement of contrast between different components of the tissue specimen, particularly as seen in light microscopy. The overall impersonal of histology is to acquire knowledge of normal tissues and organs, which is essential to understanding the altered str ucture and function of diseased cells, tissues and organs. There is no doubt that the use of dyes to allow for differentiation between normal and abnormal tissues is fundamental to our understanding of this.ReferencesBancroft, J., and Gamble, M., (2008). speculation and practice of histological techniques. PA, USA ElsevierBancroft, D. and Cook C., (1994). Manual of Histological Techniques and their diagnostic Application. PA, USAChurchill Livingstone Elsevier.Cook, D., (2008) Cellular Pathology. 2nd Edition, Chatham Scion Publishing Ltd.Kiernan, A., (1999). Histological and Histochemical Methods. Theory and suffice (3rd Ed). Oxford Butterworth-Heinemann.Lakhani, R., Dilly, A., and Finalyson, J., (1998) Basic Pathology An Introduction to the Mechanisms of Disease (2nd Ed). London Arnold.Stevens, A., and Lowe, J., (1997). Human Histology. (2nd Ed) Edinburgh Mosby.Stevens, A., and Lowe, J., (2000). Pathology 2nd Ed Mosby Edinburgh.