What is the primary method used to collect a DNA sample?

The primary method used to collect a DNA sample is a cheek swab. This method involves rubbing a sterile swab against the inside of a person's cheek to collect cells that contain DNA. Cheek swabs are favored for several reasons: they are non-invasive, relatively easy to administer, and can be performed without the need for specialized medical facilities. This ease of collection makes it a common choice in various contexts, including criminal investigations and paternity tests.

While blood draws are also a viable method for collecting DNA, they are more invasive and typically require trained medical personnel and sterile conditions. Urine tests do not yield DNA in any significant quantity, making them unsuitable for DNA analysis. Hair samples can contain DNA, but it’s usually in less abundance and more difficult to analyze unless the root is attached, which is not always the case. Thus, the cheek swab stands out for its practicality and effectiveness in DNA collection.