A COMPANY SERVE FOR STUDENTS T20 TOCOPRODUCTS & Pvt. Ltd

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

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

REDUCING THE EXAM TIME BY ONE HOUR AND MARKS BY 50

INTRODUCE BREAK AFTER EACH 30 MINUTES

GIVE FREE HIT MARKS FOR EVERY UNEXPECTED QUESTIONS

FIRST 30 mins. POWER PLAY NO SUPERVISOR IN THE HALL

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

COUNTING OF BACTERIA

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

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

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

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

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

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.

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.

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

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.

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.

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

COULTER COUNTER METHOD Flow of suspension Tube Electrode Electrode Orifice Suspension

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 .

COMPARISION WITH STANDARD SUSPENSION INDIRECT METHODS COMPARISION WITH STANDARD SUSPENSION

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.

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

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

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

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

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

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

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

THANK YOU I ACKNOWLEDGE MY MISTAKES IF ANY Meet again