1. A COMPANY SERVE FOR STUDENTS
T20 TOCOPRODUCTS & Pvt. Ltd

2. PROUDLY INTRODUCING
T20 EXAM PATTERN
BY T20 TOCO PRODUCTS & Ltd.

3. THE TAMILNADU DR. MGR MEDICAL
IN ASSOCIATION WITH
THE TAMILNADU DR. MGR MEDICAL
UNIVERSITY

4. REDUCING THE EXAM TIME BY
ONE HOUR
AND
MARKS BY 50

5. INTRODUCE BREAK
AFTER EACH 30 MINUTES

6. GIVE FREE HIT MARKS
FOR EVERY
UNEXPECTED QUESTIONS

7. FIRST 30 mins. POWER PLAY
NO SUPERVISOR
IN THE HALL

8. CHEER GIRLS IN EVERY CLASS.
THEY WILL DANCE AFTER FININSHING EVERY PAGE

10. COUNTING OF BACTERIA

11. BACTERIAL COUNT COUNT OF LIVING AND DEAD CELLS TOTAL COUNT.
COUNT OF ONLY LIVING OR VIABLE CELLS
VIABLE COUNT.

12. TOTAL COUNT METHODS Direct methods: Breed’s method Wright’s method
Counting Chamber
Coulter counter method
Membrane filtration

13. Total count methods Indirect methods: Packed cell volume Dry weight
Visual method
Photometric method
Colorimetry
Nephlometry
Packed cell volume
Dry weight

14. VIABLE COUNT SOLID MEDIA TECHNIQUE Pour plate method
Surface viable method
Drop technique
Spreading techinque

15. VIABLE COUNT ROLL TUBE METHOD MEMBRANE FILTERATION
FLUID MEDIA TECHNIQUE
COUNTING ANEAROBES

16. TOTAL COUNT – BREED’S METHOD
Microscopic slide – mark 01 sq.mm area
Place stage micrometer in the eye piece
Dilute the suspension – spread carefully on the sq.mm area of the slide – dry it – fix it – stained – counted at the squares.

17. DO YOU KNOW THESE? SIZE OF SQUARE IN THE EYEPIECE
AREA OF FLIM ON THE SLIDE
VOLUME OF SUSPENSION TAKEN on the slide
If you know ……………….
THEN THE NUMBER OF ORGANISMS IN THE ORIGINAL SUSPENSION CAN BE CALCULATED.

18. WRIGHT’S METHOD
Equal volumes of suspension and blood is intimately mixed.
Made a smear on the slide.
Fixed – stained – counted
Number of bacteria and red cells are counted for 40 fields.
Number of RBC - 5X106 per cm2

19. As the ratio of blood cells to bacteria on the slide is known, the number of bacteria per cm3 in the suspension can be found by proportionality.

20. COUNTING CHAMBER Slide with recessed area that is ruled in squares.
Drop of culture is placed over that and place a cover slip.
Don’t allow any air to entrap
Allow to settle the cells on the area
View under phase contrast microscope
Stain and focus under normal micros.

21. Number of organisms in 04 groups of 16 small squares are counted
Cover glass
Ditches
Grid
Depressed cell
Suspension cel
End view
CIRCULAR DITCH CELL
STRAIGHT DITCHES

23. COULTER COUNTER METHOD
Flow of suspension
Tube
Electrode
Electrode
Orifice
Suspension

25. MEMBRANE FILTRATION
Provided that the suspension could be sufficiently diluted
Organism retained on the filter are stained – dried – counted under microscope
The number of bacteria on the filter paper, from a known volume of suspension can be calculated
Mostly applicable when the numb of organism is very small .

26. COMPARISION WITH STANDARD SUSPENSION
INDIRECT METHODS
COMPARISION WITH STANDARD SUSPENSION

27. VISUAL METHOD Use of std. opacity tubes.
10 tubes – solid suspn. of unglazed porcelain in increasing OD.
They are standardized against accurately counted bacterial Suspension.
Comparing the opacity with standards.

28. PHOTOMETRIC METHOD CALORIMETRY
SPECIAL FILTER
OPTICAL CELL
CALORIMETRY
METER READING
PHOTO CELL
LIGHT SOURCE
NO. OF CELLS
SHUTTER
AMOUNT OF LIGHT ABSORBED BY THE SUSPENSION IS CALCULATED

29. NEPHLOMETRY
THE AMOUNT OF LIGHT REFRACTED BY THE PARTICLES IN THE SUSPENSION IS MEASURED

30. Suspension is centrifuged Depth of sediment is measured
PACKED CELL VOLUME
Suspension is centrifuged
Depth of sediment is measured
Equivalent num. of cells is obtained from a graph of cell numbers against paced cell volume

31. Centrifuged cells – washed, Weight can be related to number of cell
DRY WEIGHT
Centrifuged cells – washed,
dried – weighed
Weight can be related to number of cell

32. VIABLE COUNT ROLL TUBE METHOD
COLONIES
ROLL TUBE METHOD
SOLIDIFIED AGAR MEDIA LAYER
The rubber closure should be loosened during incubation

33. MEMBRANE FILTER IMPREGNATED WITH MEDIUM
MEMBARANE FILTRATION
MEMBRANE FILTER IMPREGNATED WITH MEDIUM
BY STEREOSPECIFIC MICROSCOPE AND SURFACE ILLUMINATOR – COUNTING CAN BE DONE
USING A FILTER OF 47 TO 50 MM DIAMETER – UP TO 200 COLONIES CAN BE COUNTED

34. FLUID MEDIA TEECHNIQUE
1 – 10 test suspension dilution in serial – find the turbidity – with dilution factor – counting is done

35. THANK YOU
I ACKNOWLEDGE MY MISTAKES IF ANY
Meet again