Combined micro-XRF and TXRF methodology for quantitative elemental imaging of tissue samples.
Combined micro-XRF and TXRF methodology for quantitative elemental imaging of tissue samples.
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DOI：
10.1016/j.talanta.2016.10.043
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发表时间：
2017
期刊：
影响因子：
6.1
通讯作者：
P. Wróbel;Sławomir Bała;M. Czyzycki;Magdalena Golasik;T. Librowski;B. Ostachowicz;W. Piekoszewski;A. Surowka;M. Lankosz
中科院分区：
文献类型：
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作者：
P. Wróbel;Sławomir Bała;M. Czyzycki;Magdalena Golasik;T. Librowski;B. Ostachowicz;W. Piekoszewski;A. Surowka;M. Lankosz
生物样本结构特性的局部差异对定量 X 射线荧光成像构成了主要限制。这是因为在经常使用的冷冻干燥过程中，不同密度的各种组织室和样品厚度的变化都会产生需要考虑的每单位面积样品质量的不同值。尽管已经提出了几种基于与厚度和密度无关的元素质量分数的量化标准来解决这个问题的解决方案，但由于样品的异质性，这个问题还没有得到充分解决。在我们最近的研究中，我们提出了一种基于外标微 X 射线荧光 (micro-XRF) 成像和内标全反射 X 射线荧光 (TXRF) 分析相结合的计算方案，以确定常用分析的大鼠组织（肾脏、肝脏和脾脏）中的校正元素质量分数分布。利用消化的大组织切片的 TXRF 分析结果以及用微型 XRF 获得的每单位面积元素质量的平均值来确定样品的每单位面积平均质量。通过使用康普顿强度来校正组织厚度和密度的变化。重要的是，由于其多功能性，我们的新方法可用于在各种生物样本中产生元素对比，其中样本密度或厚度的局部变化不再是问题。
Local differences in structural properties of biological specimens pose a major limitation to quantitative X-ray fluorescence imaging. This is because both the various tissue compartments of different density and variation in the sample thickness upon frequently used freeze-drying come up with the different values of the sample mass per unit area to be taken into account. Even though several solutions to tackle this problem based on the home-made standards for quantification in terms of thickness- and density-independent elemental mass fractions have been proposed, this issue is not addressed enough due to the samples’ heterogeneity. In our recent study, we propose a calculation scheme based on combined external-standard micro X-ray fluorescence (micro-XRF) imaging and internal-standard total reflection X-ray fluorescence (TXRF) analysis to determine the corrected elemental mass fraction distributions in commonly analysed rat tissues: kidney, liver and spleen. The results of TXRF analysis of digested large tissue sections together with the mean values of elemental masses per unit area obtained with micro-XRF were employed to determine the average masses per unit area of the samples. The correction for variation of the tissue thickness and density was done through with the use of Compton intensities. Importantly, by its versatility, our novel approach can be used to produce elemental contrast in a variety of biological specimens where local variations in either the sample density or thickness are no longer the issue.