# Bacteriophage Lab Report

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Introduction: Viral infections can affect many things, including bacteria. When bacteria undergo infections from a virus that virus is called a bacteriophage. After a bacteriophage infects a bacteria it can create two different phases, the lytic or lysogenic cycles. During a lytic stage the bacteriophage causes death to the bacteria. When this happens on an agar plate covered in bacteria it creates a clear spot known as a plaque. Each plaque is created by one virus so from the number of plaques present it is possible to govern how many viruses are in a culture. During this lab this Plaque Counting Assay was used to determine how many viruses were in the solution. The lab was to conduct a serial dilution to determine the titer of the bacteriophage …show more content…
For this lab one conversion and three different statistics were used to compare the results of the serial dilution to the original titer of the T2 Coliphage. First, the data had to be slimmed down to the numbers that are considered reliable, which is between thirty and three hundred, and there resulted in four dependable data points. These four data points were required to be converted into PFU/ml so they could be easily compared to the bacteriophages original titer. The average was the first of the statistical tests done and this required the student to add the four PFU/ml data points up and then divide by four. Standard deviation is the next statistic that was required to solve and the students had to pick between sample or population standard deviation. Sample standard deviation was choose because only a sample of the data was used for the statistics instead of the entire data. This statistic is important so the amount of variation between the data points is known (“Standard Deviation”). The equation is used to calculate this data. Once both the sample standard deviation and the average are calculated it is possible to find the last statistic, coefficient of variation. This data set is determined by dividing standard deviation by the mean. It is important to calculate because it shows the dispersion of the data points around the mean (“Coefficient Of Variation (CV)