The purpose of this experiment was to use 3 different techniques (Direct count with hemacytometer, viable count, plate count, turbidity study using spectrophotometer) to calculate the cell count and growth of bacteria, while using serial dilution. The 3 techniques were used to calculate the % viability of Serratia marcesens in a solution.
Introduction
Enumeration of microorganism is used to determine the amount of bacteria present in a sample. Microbiologists around the world are using enumeration to calculate the amount of bacteria present in drinking water and other potable drinks. Serial dilution is used to lower the amount of bacteria present in a solution, making it countable and viability let it know how viable the microorganism …show more content…
We then added 1 drop of our yeast culture to the groove of the hemacytometer. We focused the grid under 100X total magnification, Using the 25 large boxes that I observed, each one consisted of 16 smaller boxes in 4x4 pattern. In order to view an individual box, we had to focus at 400X total magnification. We then counted a 5 large box and recorded the observed number of cells in each box by using the counter. We will show you how how we used the direct count obtained to calculate the total cell count per mL of …show more content…
We obtained 8 ml of undiluted yeast culture and place it in a clean test tube labeled 1, 1:1 concentrated yeast sample. We transferred 4 ml of the yeast culture from tube 1 and place it in a second test tube, then dilute it with 4 ml of DI H2O, labeled 2, 1:2. We transferred 4 ml of yeast culture from tube 2 to another clean test tube, labeled 3, 1:4 and dilute it with 4 ml of DI H2O. We did the same thing with tube #4, labeling it 4, 1:8. We will take 4 ml from tube 4 and place it in a 5th test tube, labeling it 5, 1:16. W mixed all of them it