Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, AK, USA.
Aquatic Contaminants Research Division, Environment Canada, Burlington, Ontario, Canada.
Rapid Commun Mass Spectrom. 2021 Jan 30;35(2):e8992. doi: 10.1002/rcm.8992.
Dried blood spots (DBSs) are gaining popularity for biomarker analyses in ecological research due to their advantages for use in field-based research and in remote settings; however, many DBS biomarkers remain unvalidated. We validated the application of compound-specific stable nitrogen isotope analyses of amino acids (CSIA-AAs) to field-prepared DBSs for determining trophic positions of wild-caught Arctic char (Salvelinus alpinus).
Whole blood and muscle from Arctic char were collected, and DBSs were created in the field. We measured the stable nitrogen isotope ratios (expressed as δ N values) of the amino acids glutamic acid (Glu) and phenylalanine (Phe) isolated from Arctic char samples using CSIA-AAs. We then compared amino acid δ N values from DBSs and the other sample types (whole blood and muscle) from the same specimens. We calculated and compared trophic position estimates generated from whole blood, DBSs, and muscle.
The δ N values of Glu and Phe, as well as trophic position estimates from DBSs, were highly correlated with δ N values and estimates from both whole blood and muscle. The DBS amino acid δ N values and trophic position estimates agreed well with those from whole blood. Although mean differences between amino acid δ N values from DBSs and muscle were noted, the offsets were small and resulted in a 0.2 mean difference between trophic position estimates for DBSs and muscle.
We demonstrate that the application of CSIA-AAs to field-prepared DBSs of Arctic char generates similar trophic position estimates to those from whole blood and muscle. We suggest that DBSs could be developed as a minimally invasive sampling technique to study feeding ecology of wild fish and perhaps other organisms of interest.
由于在基于野外的研究和偏远环境中使用具有优势，干血斑 (DBS) 在生态研究中的生物标志物分析中越来越受欢迎；然而，许多 DBS 生物标志物仍未得到验证。我们验证了应用于野外制备的 DBS 中用于确定野生北极鳕鱼（Salvelinus alpinus）营养位置的氨基酸的化合物特异性稳定氮同位素分析（CSIA-AAs）。
采集北极鳕鱼的全血和肌肉，并在野外制作 DBS。我们使用 CSIA-AAs 测量从北极鳕鱼样本中分离出的氨基酸谷氨酸 (Glu) 和苯丙氨酸 (Phe) 的稳定氮同位素比值（表示为 δ N 值）。然后，我们比较了来自 DBS 和其他样本类型（全血和肌肉）的氨基酸 δ N 值。我们计算并比较了来自全血、DBS 和肌肉的营养位置估计值。
Glu 和 Phe 的 δ N 值以及来自 DBS 的营养位置估计值与来自全血和肌肉的 δ N 值和估计值高度相关。DBS 氨基酸 δ N 值和营养位置估计值与全血吻合良好。尽管注意到来自 DBS 的氨基酸 δ N 值与肌肉之间存在平均差异，但这些差异很小，导致 DBS 和肌肉的营养位置估计值之间存在 0.2 的平均差异。
我们证明了将 CSIA-AAs 应用于野外制备的北极鳕鱼 DBS 可以生成与全血和肌肉相似的营养位置估计值。我们建议可以将 DBS 开发为一种微创采样技术，用于研究野生鱼类和其他感兴趣的生物的摄食生态。
