20.500.12556/DiRROS-28823 Strategies to overcome hematocrit and volume bias in dried blood spot analysis Background/Objectives: Dried blood spot (DBS) sampling, a technique for collecting capillary blood samples, is widely used in therapeutic drug monitoring, pharmacokinetic and toxicology research, newborn screening, and population health because it enables simple, non-invasive sampling across large cohorts. However, it presents several challenges, mainly due to the effect of hematocrit (HCT), which can influence the quantification of analytes. Methods: A combination of methods was developed to estimate the HCT and blood volume in DBS samples. Image analysis and hemoglobin (Hb) quantification using UV-VIS spectrometry were used for HCT estimation, and conductivity was used to determine blood volume. DBS samples from five donors were prepared with HCT between 0.2 and 0.6 and were used to prepare calibrators and quality control samples. The developed methods were applied to 23 samples obtained from ten adult patients with inflammatory bowel disease. Results: The methods for HCT determination using image analysis or Hb measurements were linear (r2 > 0.994), with acceptable accuracy (90.3–102.2%) and precision (<7.4%). Moreover, the conductivity method was linear (r2 = 0.999) and enabled accurate (96.8–100%) and precise (<5.65%) determination of blood volume in DBS samples. All three methods were in good agreement with the reference values in patient samples. Finally, strategies to correct HCT- and volume-related bias in DBS samples were proposed for analytes with different blood cell-to-plasma partition coefficients. Conclusions: We accurately and precisely estimated HCT in DBS samples using image analysis and Hb determination, and the volume of blood in DBS using conductivity measurement. We evaluated different approaches and derived an optimal procedure for HCT-bias correction. dried blood spots DBS microsampling blood volume hematocrit image analysis conductivity spectrometry bias posušene krvne kapljice DBS mikrovzorčenje volumen krvi hematokrit analiza slike prevodnost spektrometrija pristranskost true false false Angleški jezik Slovenski jezik Neznano 2026-04-08 13:11:02 2026-04-08 13:11:03 2026-04-09 03:51:22 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Opis vira z dne 2. 3. 2026; str. 1-17 str. iss. 3, [article no.] 403 Vol. 19 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 615.38 1424-8247 10.3390/ph19030403 270022147 RAZ_Mingas_Panagiotis-Dimitrios_2026.pdf RAZ_Mingas_Panagiotis-Dimitrios_2026.pdf 1 D96B3C953ACA44620D60CF7ECA88B1A3 c133eced9d0ff1bc54cfce31ff7398d20d9122559dc6761b39f8ca1a84295cb5 c920c09d-333b-11f1-b941-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=42946 https://www.mdpi.com/1424-8247/19/3/403 1 a3c358ff-333b-11f1-b941-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=42945 Univerzitetni klinični center Ljubljana 0 0 0