When using hair samples for DNA purposes, from which part of the animal should the hair be collected?

When using hair samples for DNA purposes, from which part of the animal should the hair be collected?

• A. Root
• B. Tip
• C. Switch
• D. End

Answer: (C)

DNA for testing comes from the cells in the hair follicle, not from the hair shaft itself. That’s why you want a hair sample that includes the root with attached follicle. In practice, the tail switch is often used as the collection site because it’s easy to access and you can pull hairs with the root still attached, giving you DNA while minimizing contamination and stress to the animal. Hair from the tip or the end of a strand typically lacks enough follicular tissue for reliable DNA yield, and even the root without the follicle isn’t as dependable. So using hair from the tail switch provides the best balance of practicality and having the necessary DNA in the sample.

DNA for testing comes from the cells in the hair follicle, not from the hair shaft itself. That’s why you want a hair sample that includes the root with attached follicle. In practice, the tail switch is often used as the collection site because it’s easy to access and you can pull hairs with the root still attached, giving you DNA while minimizing contamination and stress to the animal. Hair from the tip or the end of a strand typically lacks enough follicular tissue for reliable DNA yield, and even the root without the follicle isn’t as dependable. So using hair from the tail switch provides the best balance of practicality and having the necessary DNA in the sample.