After the DNA sample is destroyed, Elisabeth still determines that it is a female's blood, narrowing the search from 84 to 47 suspects.
The number 47 is a favorite of the Star Trek veterans on the writing and production staff of Terra Nova. The inclusion of the number 47 started on Star Trek: The Next Generation (1987) by writer/co-producer Joe Menosky and was quickly adopted by the rest of the writing and production team. The tradition of including the number 47 in inconspicuous places continued in Star Trek: Deep Space Nine (1993), Star Trek: Voyager (1995), Star Trek: Enterprise (2001), and Alias (2001).
Menosky said that he chose that particular number because when he was a graduate student at Pomona College, Professor of Mathematics Donald Bentley proved as a joke that all numbers are equal to 47.
Malcom says the drop of blood in paint sealant is useless because the toluene in the sealant destroys red blood cells. There are a few problems here. Red blood cells do no contain the nuclear DNA used in identifying folks. White blood cells make DNA fingerprinting possible. To reach that DNA the white cells and their nuclei must be lysed, aka destroyed.