厦门大学：《现代生物实验学》课程教学课件（PPT讲稿）lab1－细菌的革兰氏染色

实验一 细菌的革兰氏染色 一 教学要求 了解不同的细菌染色方法的原理，掌握革兰氏 染色方法的操作技术。 二 实验原理 1、染色方法 Since bacteria are almost colorless and therefore show little contrast with the broth in which they are suspended, they are difficult to observe when unstained. Staining microorganisms enables one to: -see greater contrast between the organism and the background, differentiate various morphological types (by shape, arrangement, gram reaction, etc.), -observe certain structures (flagella, capsules, endospores, etc.)

实验一 细菌的革兰氏染色 一 教学要求 了解不同的细菌染色方法的原理，掌握革兰氏 染色方法的操作技术。 二 实验原理 1、染色方法 Since bacteria are almost colorless and therefore show little contrast with the broth in which they are suspended, they are difficult to observe when unstained. Staining microorganisms enables one to: -see greater contrast between the organism and the background, differentiate various morphological types (by shape, arrangement, gram reaction, etc.), -observe certain structures (flagella, capsules, endospores, etc.)

•Simple stains Simple stains highlight the organism so basic structures are visible in microscope. • Differential stains Differential stains react differently with different kinds of bacteria. • Special stains Used to color and isolate various structures, such as capsules, endospores, and flagella

•Simple stains Simple stains highlight the organism so basic structures are visible in microscope. • Differential stains Differential stains react differently with different kinds of bacteria. • Special stains Used to color and isolate various structures, such as capsules, endospores, and flagella

Simple stains

Simple stains

2、革兰氏染色 ⚫ Gram Stain - developed Christian Gram in 1884 ⚫ The gram stain is the most widely used staining procedure in bacteriology. It is called a differential stain since it differentiates between gram-positive and gram-negative bacteria. Bacteria which stain purple with the gram staining procedure are termed gram-positive; those which stain pink are said to be gram￾negative. ⚫ Gram-positive and gram-negative bacteria stain differently because of fundamental differences in the structure of their cell walls

2、革兰氏染色 ⚫ Gram Stain - developed Christian Gram in 1884 ⚫ The gram stain is the most widely used staining procedure in bacteriology. It is called a differential stain since it differentiates between gram-positive and gram-negative bacteria. Bacteria which stain purple with the gram staining procedure are termed gram-positive; those which stain pink are said to be gram￾negative. ⚫ Gram-positive and gram-negative bacteria stain differently because of fundamental differences in the structure of their cell walls

Structure of a Gram-Negative Cell Wall Structure of a Gram-Positive Cell Wall

Structure of a Gram-Negative Cell Wall Structure of a Gram-Positive Cell Wall

三 材料与器材 ⚫ 菌种： 大肠杆菌约24 h营养琼脂斜面培 养物，金黄色葡萄球菌约24 h 营养琼脂 斜面培养物。 ⚫ 革兰氏染色液 ⚫ 载玻片、酒精灯、显微镜

三 材料与器材 ⚫ 菌种： 大肠杆菌约24 h营养琼脂斜面培 养物，金黄色葡萄球菌约24 h 营养琼脂 斜面培养物。 ⚫ 革兰氏染色液 ⚫ 载玻片、酒精灯、显微镜

四 操作步骤 制片（涂片，干燥，固定）→初染（草酸铵结晶 紫染1 min，水洗）→媒染（加碘液覆盖涂面染1 min，水洗，用吸水纸吸去水分）→脱色（加 95%酒精数滴，并轻轻摇动进行脱色，20 s后水 洗，用吸水纸吸去水分）→复染（蕃红复染约1 min，水洗）→干燥→镜检

四 操作步骤 制片（涂片，干燥，固定）→初染（草酸铵结晶 紫染1 min，水洗）→媒染（加碘液覆盖涂面染1 min，水洗，用吸水纸吸去水分）→脱色（加 95%酒精数滴，并轻轻摇动进行脱色，20 s后水 洗，用吸水纸吸去水分）→复染（蕃红复染约1 min，水洗）→干燥→镜检

Smear preparation

Smear preparation

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Staining Heat fixing

Staining Heat fixing