Question

1. Assessing accuracy and proficiency: Do you get the same result if you measure the same dilution tube twice? What are some reasons you might not get the same measurement? 2. Does this OD reading tell you how many live cells are in culture? What advantages are there to measuring cells with the s What disadvantages? 3. How confident are you that you accurately identified the concentration of pigment? List three caveats to your conclusion about the concentration of pigment in your spent medium: 4. If you isolated a bacterium from nature or from a patient and it produced a soluble pigment, how cculd you characterize it?

Answer 1

1. If you measure the same dilution tube twice, you may not get the same results in each measurement. You will probably get slightly different measurements. This happens because the instruments are limited in their sensitivity and precision. The first refers to the smallest variation that the instrument is capable of measuring, and the second refers to how accurate the measurements are with respect to the real values.
There are no 100% accurate and sensitive instruments, which is why it is important to carry out many measurements, in order to obtain an average value.