This World Health Organization manual provides guidelines for HIV drug resistance testing using dried blood spot (DBS) specimens. Aimed at laboratory professionals in low- and middle-income countries, it emphasizes best practices for preparation, storage, and shipping of DBS as an alternative to plasma specimens. The manual discusses the advantages of using DBS, such as ease of transport and minimal processing requirements, though it also notes limitations like reduced sensitivity in viral RNA amplification due to low specimen volume. It offers standardized methods to validate and perform genotyping, contributing to global strategies for assessing HIV drug resistance. The manual includes protocols from various institutions and highlights the importance of proper specimen handling to ensure accurate results.