서혜진 (한국과학기술연구원)

최만호 (한국과학기술연구원)

서혜진 (한국과학기술연구원)

오한빈 (서강대학교)

최만호 (한국과학기술연구원)

Although dried blood spot (DBS) sampling offers ease of collection, minimal sample volume, and convenient storage. The effect of hematocrit on the quantitative analysis of sterols and steorids remains poorly understood. To assess intra-spot variability, three punches were collected from the outer-edge and one from the central of 6-mm i.d. spots. In addition, central regions of 11.5-mm and 6-mm spots were compared to evaluate the impact of sample volume using gas chromatography-mass spectrometry (GC-MS). In 6-mm spots, the levels of sterols and steroids were slightly higher in the outer-edge punches than in the center. Especially, cortisol levels were 0.48 ± 0.21 ng at the edge vs. 0.18 ± 0.10 ng at the center, cortisone (0.09 ± 0.05 ng vs. 0.04 ± 0.02 ng), and pregnenolone (0.30 ± 0.21 ng vs. 0.20 ± 0.13 ng). Similar trends were observed for sterols: cholesterol (9.67 ± 2.48 μg vs. 8.84 ± 2.47 μg), lathosterol (5.01 ± 2.29 ng vs. 4.70 ± 2.22 ng), lanosterol (1.76 ± 0.82 ng vs. 1.68 ± 0.71 ng), 7α-OHC (23.84 ± 17.47 ng vs. 20.82 ± 15.91 ng), and 7β-OHC (16.83 ± 13.78 ng vs. 14.35 ± 12.93 ng). Comparison of 11.5-mm and 6-mm spots provided that DHEA, THF, and 5α-DHP were detectable only in the larger spots. Both spot location and sample size affected the quantitative results of sterols and steroids in DBS, indicating intra-spot variability. These findings reveal practical guidance for optimizing DBS sampling and highlight the importance of standardization in DBS-based sterol and steroid analysis.

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