{"id":598,"date":"2022-02-13T01:12:39","date_gmt":"2022-02-13T00:12:39","guid":{"rendered":"https:\/\/pedagogie.ac-lille.fr\/svt\/?p=598"},"modified":"2022-09-14T16:43:02","modified_gmt":"2022-09-14T14:43:02","slug":"lugol-et-coloration-foliaire-en-toute-securite","status":"publish","type":"post","link":"https:\/\/pedagogie.ac-lille.fr\/svt\/lugol-et-coloration-foliaire-en-toute-securite\/","title":{"rendered":"Lugol et coloration foliaire en toute s\u00e9curit\u00e9"},"content":{"rendered":"

Des accidents multiples li\u00e9s \u00e0 l\u2019utilisation de l\u2019alcool bouillant pour d\u00e9colorer les feuilles de G\u00e9ranium ont conduit \u00e0 interdire cette pratique dans le cadre des activit\u00e9s sur la photosynth\u00e8se. L\u2019utilisation d\u2019un Lugol tr\u00e8s concentr\u00e9 est une alternative \u00e0 cette technique.
\nL\u2019exemple ci-dessous donne pour une feuille de G\u00e9ranium \u00e9clair\u00e9e pendant 48 h (simple lampe de dissection) un moyen d\u2019\u00e9viter la d\u00e9coloration par l\u2019alcool bouillant.<\/p>\n

\"\"<\/a><\/p>\n

La feuille a \u00e9t\u00e9 plac\u00e9e dans l\u2019eau bouillante pendant 10 minutes, puis directement color\u00e9e par le Lugol tr\u00e8s concentr\u00e9 utilis\u00e9 dans la m\u00e9thode Gram : 2 g d\u2019iodure de potassium et 1 g d\u2019iode m\u00e9tallo\u00efde I2 dans 100 mL d\u2019eau distill\u00e9e<\/strong><\/p>\n

L’utilisation de diiode et l’iodure de potassium ne sont toutefois pas sans risque. L\u2019utilisation de la blouse, des lunettes et des gants est indispensable.
\nDes r\u00e9sultats \u00e9quivalents peuvent \u00eatre obtenus sur des feuilles panach\u00e9es ou non de Lierre (meilleure tenue de la feuille apr\u00e8s coloration).<\/p>\n

 <\/p>\n

PREVOST Didier – Lyc\u00e9e Guy Mollet ARRAS<\/p>\n","protected":false},"excerpt":{"rendered":"

Des accidents multiples li\u00e9s \u00e0 l\u2019utilisation de l\u2019alcool bouillant pour d\u00e9colorer les feuilles de G\u00e9ranium ont conduit \u00e0 interdire cette pratique dans le cadre des activit\u00e9s sur la photosynth\u00e8se. L\u2019utilisation […]<\/p>\n","protected":false},"author":50,"featured_media":599,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28],"tags":[],"class_list":{"0":"post-598","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-labo","8":"czr-hentry"},"publishpress_future_action":{"enabled":false,"date":"2026-04-13 13:58:32","action":"change-status","newStatus":"draft","terms":[],"taxonomy":"category","extraData":[]},"publishpress_future_workflow_manual_trigger":{"enabledWorkflows":[]},"_links":{"self":[{"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/posts\/598","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/users\/50"}],"replies":[{"embeddable":true,"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/comments?post=598"}],"version-history":[{"count":5,"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/posts\/598\/revisions"}],"predecessor-version":[{"id":779,"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/posts\/598\/revisions\/779"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/media\/599"}],"wp:attachment":[{"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/media?parent=598"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/categories?post=598"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pedagogie.ac-lille.fr\/svt\/wp-json\/wp\/v2\/tags?post=598"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}