{"id":10232,"date":"2023-12-01T05:04:35","date_gmt":"2023-12-01T08:04:35","guid":{"rendered":"https:\/\/mol-en.icb.usp.br\/?page_id=10232"},"modified":"2026-03-22T13:03:56","modified_gmt":"2026-03-22T16:03:56","slug":"1-1-basic-concepts","status":"publish","type":"page","link":"https:\/\/mol-en.icb.usp.br\/index.php\/1-1-basic-concepts\/","title":{"rendered":"1-1 Basic concepts"},"content":{"rendered":"<div class=\"su-row\">\n<div class=\"su-column su-column-size-1-1\"><div class=\"su-column-inner su-u-clearfix su-u-trim\"><strong> A HISTOLOGICAL SLIDE<\/strong> <\/div><\/div>\n<\/div>\n<div class=\"su-column su-column-size-1-2\"><div class=\"su-column-inner su-u-clearfix su-u-trim\"><\/div><\/div>\nThe histological slide is a rectangular glass slide on which isolated cells, bacteria, protozoa, fungi,  very thin slices of tissues and organs and other microscopic objects are placed.<br \/>\nThe slices are called <strong>histological sections<\/strong> or <strong>tissue sections<\/strong>. For their protection, they are covered with a thin sheet of glass, the <strong>coverslip<\/strong>, that is glued over the slide.<\/p>\n<p>The most usual dimension used in Histology: the <strong>\u00b5m<\/strong> (micrometer). It measures 1 thousandth of a millimeter = 1 millionth of a meter. Tissue or organ slices for observation under an optical microscope measure usually 2 to 10 \u00b5m in thickness.<br \/>\n\u200b<br \/>\nPermanent histological slides are made to last many years. To obtain a permanent histological slide: isolated cells or fragments of tissues and organs undergo several procedures that begin with their <strong>fixation <\/strong>. Fixation maintains their structure and some of their chemical composition during the further stages of the whole process. It is carried out by chemical means (e.g. with formaldehyde) or by physical means (e.g. by freezing the specimens).<br \/>\nFollowing fixation, the small fragments of tissues and organs undergo a sequence of steps to allow them to be cut in a device, the <strong>microtome<\/strong>, to obtain histological sections. To be studied with a light microscope the sections as well as isolated cells are placed on glass slides.<br \/>\nCells as well as tissue and organ sections are almost always colorless and need to be stained to allow their observation with a microscope. After the staining procedure they are covered with a coverslip for their protection.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-9516\" src=\"https:\/\/mol-en.icb.usp.br\/wp-content\/uploads\/1-1-en.jpg\" alt=\"\" width=\"450\" height=\"434\" \/><\/p>\n<p>Liver. Staining: hematoxylin and eosin (HE). Medium magnification.<\/p>\n<p><a href=\"https:\/\/mol-en.icb.usp.br\/index.php\/1-2-basic-concepts-2\/\">NEXT PAGE<\/a><\/p>\n<p><a href=\"https:\/\/mol-en.icb.usp.br\/index.php\/1-0-basic-concepts\/\">MENU OF THIS CHAPTER<\/a><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The histological slide is a rectangular glass slide on which isolated cells, bacteria, protozoa, fungi, very thin slices of tissues and organs and other microscopic objects are placed. The slices are called histological sections or tissue sections. For their protection, they are covered with a thin sheet of glass, the coverslip, that is glued over [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-10232","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/mol-en.icb.usp.br\/index.php\/wp-json\/wp\/v2\/pages\/10232","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mol-en.icb.usp.br\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/mol-en.icb.usp.br\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/mol-en.icb.usp.br\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/mol-en.icb.usp.br\/index.php\/wp-json\/wp\/v2\/comments?post=10232"}],"version-history":[{"count":55,"href":"https:\/\/mol-en.icb.usp.br\/index.php\/wp-json\/wp\/v2\/pages\/10232\/revisions"}],"predecessor-version":[{"id":19986,"href":"https:\/\/mol-en.icb.usp.br\/index.php\/wp-json\/wp\/v2\/pages\/10232\/revisions\/19986"}],"wp:attachment":[{"href":"https:\/\/mol-en.icb.usp.br\/index.php\/wp-json\/wp\/v2\/media?parent=10232"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}