{"id":359,"date":"2021-01-05T04:40:04","date_gmt":"2021-01-05T04:40:04","guid":{"rendered":"https:\/\/laboratoryinfo.com\/?p=359"},"modified":"2022-03-07T19:39:55","modified_gmt":"2022-03-07T19:39:55","slug":"alkaline-congo-red-staining-technique-for-amyloid","status":"publish","type":"post","link":"https:\/\/laboratoryinfo.com\/alkaline-congo-red-staining-technique-for-amyloid\/","title":{"rendered":"Alkaline Congo Red Staining Technique for Amyloid : Principle, Procedure and Interpretation"},"content":{"rendered":"\n<p>Amyloid refers to the abnormal, fibrous, extracellular proteinaceous deposits found in organs such as liver, kidneys, spleen etc.<\/p>\n\n\n\n<p>This condition of deposition of amyloid in tissues is known as Amyloidosis. Congo red histological staining technique is the gold standard technique for the diagnosis of amyloidosis.<\/p>\n\n\n<style>.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-table-of-content-wrap{padding-top:var(--global-kb-spacing-sm, 1.5rem);padding-right:var(--global-kb-spacing-sm, 1.5rem);padding-bottom:var(--global-kb-spacing-sm, 1.5rem);padding-left:var(--global-kb-spacing-sm, 1.5rem);background-color:#ecf2f7;}.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-table-of-contents-title-wrap{padding-top:0px;padding-right:0px;padding-bottom:0px;padding-left:0px;}.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-table-of-contents-title{font-weight:regular;font-style:normal;}.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-table-of-content-wrap .kb-table-of-content-list{font-weight:regular;font-style:normal;margin-top:var(--global-kb-spacing-sm, 1.5rem);margin-right:0px;margin-bottom:0px;margin-left:0px;}.kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-basiccircle .kb-table-of-contents-icon-trigger:after, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-basiccircle .kb-table-of-contents-icon-trigger:before, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-arrowcircle .kb-table-of-contents-icon-trigger:after, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-arrowcircle .kb-table-of-contents-icon-trigger:before, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-xclosecircle .kb-table-of-contents-icon-trigger:after, .kb-table-of-content-nav.kb-table-of-content-id6113_3b9ebd-8c .kb-toggle-icon-style-xclosecircle .kb-table-of-contents-icon-trigger:before{background-color:#ecf2f7;}<\/style>\n\n\n<h2 class=\"wp-block-heading\">Principle<\/h2>\n\n\n\n<p>Congo red dye forms nonpolar hydrogen bonds with amyloid and red to apple green birefringence occurs when viewed by polarized light due to alignment of dye molecules on the lineraly arranged amyloid fibrils. The high pH enhances the non-polar hydrogen bonding of congo red and amyloid.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Requirements<\/h2>\n\n\n\n<ol><li>Meyer&#8217;s Hematoxylin<\/li><li>Congo red stock solution<\/li><\/ol>\n\n\n\n<blockquote class=\"wp-block-quote\"><p>Congo red = 0.3 gm<br>Sodium Chloride = 0.3 gm<br>80% alcohol = 100 ml<\/p><\/blockquote>\n\n\n\n<ul><li>NaOH solution<\/li><\/ul>\n\n\n\n<blockquote class=\"wp-block-quote\"><p>NaOH = 1 gm<br>Distilled water = 100 ml<\/p><\/blockquote>\n\n\n\n<ul><li>Working congo red<\/li><\/ul>\n\n\n\n<blockquote class=\"wp-block-quote\"><p>1% NaOH = 0.5 ml<br>Congo red stock solution = 50 ml<\/p><\/blockquote>\n\n\n\n<ul><li>Alkaline alcohol solution<\/li><\/ul>\n\n\n\n<blockquote class=\"wp-block-quote\"><p>1% NaOH = 1 ml<br>50% Alcohol = 100 ml<\/p><\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\">Procedure<\/h2>\n\n\n\n<ol><li>Deparaffinize and bring sections to distilled water.<\/li><li>Stain in congo red working solution for 10 minutes.<\/li><li>Rinse in distilled water.<\/li><li>Differentiate quickly (9-10 dips) in alkaline alcohol solurion.<\/li><li>Rinse in tap water.<\/li><li>Counterstain with Meyer&#8217;s Hematoxylin for 30 seconds.<\/li><li>Dip in ammonia water for 30 seconds until sections turn blue.<\/li><li>Rinse in distilled water for 10 minutes.<\/li><li>Dehydrate, clear and mount.<\/li><\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">Result and Interpretation<\/h2>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><a href=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-tissue-section.jpg\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-tissue-section.jpg\" alt=\"congo-red-stain\" class=\"wp-image-360\" width=\"500\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-tissue-section.jpg 622w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-tissue-section-300x172.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-tissue-section-20x11.jpg 20w\" sizes=\"(max-width: 622px) 100vw, 622px\" \/><\/a><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><strong>Amyloid<\/strong>&nbsp;: Red to Pink<\/p>\n\n\n\n<p class=\"has-text-align-center\"><strong>Nucleus<\/strong>&nbsp;: Blue<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter size-full is-resized\"><a href=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-stain-polarized.jpg\"><img decoding=\"async\" src=\"http:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-stain-polarized.jpg\" alt=\"congo-red-stain-polarized\" class=\"wp-image-361\" width=\"500\" srcset=\"https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-stain-polarized.jpg 650w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-stain-polarized-300x225.jpg 300w, https:\/\/laboratoryinfo.com\/wp-content\/uploads\/2015\/05\/congo-red-stain-polarized-20x15.jpg 20w\" sizes=\"(max-width: 650px) 100vw, 650px\" \/><\/a><\/figure><\/div>\n\n\n\n<p class=\"has-text-align-center\"><strong>In Polarizing Microscope<\/strong>&nbsp;: Red to Green birefringence<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Amyloid refers to the abnormal, fibrous, extracellular proteinaceous deposits found in organs such as liver, kidneys, spleen etc. This condition of deposition of amyloid in tissues is known as Amyloidosis. Congo red histological staining technique is the gold standard technique for the diagnosis of amyloidosis. Principle Congo red dye forms nonpolar hydrogen bonds with amyloid&#8230;<\/p>\n","protected":false},"author":4,"featured_media":361,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"rank_math_lock_modified_date":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[7],"tags":[26,38],"acf":[],"_links":{"self":[{"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/posts\/359"}],"collection":[{"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/comments?post=359"}],"version-history":[{"count":0,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/posts\/359\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/media\/361"}],"wp:attachment":[{"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/media?parent=359"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/categories?post=359"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/laboratoryinfo.com\/wp-json\/wp\/v2\/tags?post=359"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}