Scene 1 (0s)
Presented by Dr.G.Shalini Assistant Professor, Dept of Biotechnology, PSGRKCW.
Scene 2 (15s)
PSGR KCW CELEBRATING WOMEN SINCE 1963. Bacterial Culture Methods.
Scene 3 (36s)
PSGR KCW CELEBRATING WOMEN SINCE 1963. Tube Dilution Method Purpose: The tube dilution method is used to determine the Minimum Inhibitory Concentration and Minimum Lethal Concentration (MLC) of an antimicrobial agent against bacteria. Preparation: A series of test tubes are prepared, each containing a nutrient growth medium. Addition of Antimicrobial Agent: Different, increasing concentrations of the antimicrobial substance are added to each tube. Inoculation: Each tube is then inoculated with a fixed, standardized amount of bacterial culture.The tubes are incubated at an appropriate temperature to allow bacterial growth..
Scene 4 (1m 0s)
PSGR KCW CELEBRATING WOMEN SINCE 1963. Sample to be counted 9-ml broth 1/10 (10-1) 1/100 (10-2) 1/103 (10-3) 1/104 (10-4) 1/106 (10-6) Colony of (bacteria): A cluster of cells (or clones) which arise from a single bacterium by asexual reproduction 1/106 (10-0) Plate -ml samples Too many colonies colonies colonies colonies colonies to count 159 x 103 = 1.59 x 106 Plato Dilution count factor Cells (colony- forming units) por milliliter of original sample Colony count multiplied by the dilution factor.
Scene 5 (1m 19s)
PSGR KCW CELEBRATING WOMEN SINCE 1963. Streak plate.
Scene 6 (1m 45s)
PSGR KCW CELEBRATING WOMEN SINCE 1963. Inoculation procedure (flame loop between streaks) Formation of discrete colonies.
Scene 7 (1m 51s)
Spread plate The spread plate method is based on the principle that each viable (living) microorganism present in a sample will grow and multiply into a visible, separate colony when spread evenly on the surface of a solid nutrient medium. Procedure Prepare and solidify nutrient agar plates. Make serial dilutions of the sample. Pipette 0.1 mL of the diluted sample onto the agar surface. Spread the sample evenly using a sterile L-shaped glass rod. Incubate the plates at the suitable temperature (usually 35–37°C) for 24–48 hours. Count the number of colonies formed on the plate. Calculate the number of viable microorganisms (CFU/mL) in the original sample..
Scene 8 (2m 20s)
PSGR KCW CELEBRATING WOMEN SINCE 1963. 1 Pipette bacterial sample onto surface of agar plate 2 Incubate Spread sample evenly over surface 3 Colonies grow on surface.
Scene 9 (2m 29s)
Pour plate The pour plate method is based on mixing a diluted microbial sample with molten agar and pouring it into Petri dishes. Individual cells become trapped in the agar and grow into separate colonies after incubation. It helps in counting and isolating microorganisms present in a sample. Procedure Prepare serial dilutions of the sample to get a countable number of microorganisms. Pipette 1 mL of the selected dilution into a sterile Petri dish. Pour about 15–20 mL of molten, cooled agar (45–50°C) into the dish. Gently swirl the plate to mix the sample evenly with the agar. Allow the agar to solidify at room temperature. Incubate the plates in an inverted position at the suitable temperature. After incubation, count the colonies (both surface and subsurface) to calculate the number of microorganisms (CFU/mL)..
Scene 10 (3m 3s)
PSGR KCW CELEBRATING WOMEN SINCE 1963. Pour Plate Method 1 3 Pipette bacterial sample onto petri dish Swirl to mix Incubate 2 4 Pour liquid nutrient agar Colonies grow on agar surface and subsurface.
Scene 11 (3m 13s)
THANK YOU. PSGR KCW CELEBRATING WOMEN SINCE 1963.