DSS

DSS can be prepared by spotting and drying serum drops onto a filter paper card. While other dried spot analytes are often applied in HIVDRT, DSS usage is rarely reported, even though the suitability of DSS for HIVDRT has been confirmed [48–51]. HIV PR and RT gene amplification was achieved from >86% of DSS specimens with VL >10,000 copies/mL [49]. DSS showed a good consistency under conditions representative of field conditions [48]. These support DSS as an alternative specimen for scaled HIVDR surveillance or even centralized HIVDR monitoring tests in RLS. Similar to DPS, the lack of a more stable HIV proviral DNA component in DSS compared to DBS results in a lower success rate of HIVDR typing. However, the DSS-based HIVDR profiling is expected to be comparable with plasma or serum. Strategies that may improve the long-term HIV viral RNA stability in DPS and DSS specimens would significantly improve the suitability of such analytes for more broad HIV molecular assays, including HIVDRT. In addition, a modified experimental design with shorter amplicons also enhances the robustness of DSS or DPS-based HIVDRT [52].

#### 2.5.2. Dried Analytes Collected with the Newer Generation of Devices

Besides the filter paper card, a newer generation of dried specimen collection devices has been developed since the early 2010s. Two exemplary product series of this category, HemaSpotTM and ViveSTTM, are described below:
