388 DIY Science: Illustrated Guide to Home Chemistry Experiments
FIGURE 22-1: Swabs showing negative (left) and positive results
for the presence of blood
RQEWEvI UESTIOnS
q 1 : You perform this test on a control sample that is known not to contain blood, but the test results are positive. What might the
sample contain that produces the false positive results?
q: 2 As a forensic specialist, you are provided with a sample and asked to use this test to determine whether blood is present. You
know that you will have to testify in court about the results of your test. Other than testing the sample itself, what other actions might
you take to ensure that your testimony is accepted as valid?