Botany (Hons) Microbiology paper (DSC-1) Practical - bacterial structure , fission, types, root nodule and Gram staining are demonstrated

1. Microbiology Practical
DSC Paper 1 (CBCS) Botany
Hons course
Dr. Rita Som Paul
Botany Department
Siliguri College
Siliguri

2. Electron micrograph of bacteria and their
types,binary fission,endospore, conjugation, root
n

3. Types of bacteria.

4. Binary fission.
• Binary fission

5. Endospore.
• Endospore

6. Conjugation.

7. Root nodule.
Nodule LS TS

8. Gram staining
• Acceptance of stains is an important
property of bacteria and is the basis for
division of bacteria to 2 main groups-
• Gram positive and Gram negative

10. GRAM STAINING PROCEDURE
• The slide should be grease free and detergent
free
• Prepare a heat fixed single-layer smear of the
culture you wish to examine
• Flood the smear with crystal violet (30 sec. to
2 min)
• Quickly and gently wash off excess stain (2
seconds) with tap water
• Flood the smear with Grams iodine (1
minute)
• Decolorize with alcohol (10-20 seconds or
until the excess alcohol which flow off the
slide is colourless)
• Quickly and gently wash off excess stain (2
seconds) with tap water
• Flood the smear with safranin (carbolfuchsin)
(30 sec to 2 min.)
• Quickly and gently wash off excess stain (2
seconds)
• Blot dry with blotting paper
• Examine your slide under the microscope.
Record sketches of the organisms, size, color,
morphology, and culture identification.

12. Eg. Bacillus, Staphylococcus Eg. Escherichia coli,Salmonella sp.

13. G+ G-