Which of the following is the preferred sample for DNA extraction?

Whole blood with ACD anticoagulant is the preferred sample for DNA extraction due to several reasons. ACD (Acid-Citrate-Dextrose) is an anticoagulant that preserves the integrity of the DNA while preventing the coagulation of blood, which is essential for obtaining high-quality DNA. This type of sample maintains cell viability and minimizes cellular degradation, ensuring that the DNA can be extracted effectively and is suitable for subsequent analysis.

Additionally, ACD-treated samples help inhibit cellular metabolism, preventing the release of nucleases that can degrade DNA. Moreover, this anticoagulant is commonly used in clinical settings for DNA extraction purposes, making it a standard choice for laboratories aiming to ensure reliable and reproducible results.

In contrast, whole blood without anticoagulants can lead to coagulation, which can hinder the extraction process and potentially yield a lower quality DNA sample. Red blood cells alone provide no nucleated cells for DNA extraction, as mature red blood cells lack nuclei. Heparinized serum may also introduce factors that compromise the integrity of DNA or lead to contaminants that could affect downstream applications. Thus, using whole blood with ACD is optimal for successful DNA extraction and analysis.