基于HTX TM-Sprayer基质喷雾仪提升MALDI质谱成像
在过去几十年中,MALDI质谱成像技术已被广泛应用在生物标志物发现和药物研发等多个领域。但是MALDI质谱成像的技术操作中,要获得高质量、重复性好的质谱结果,并不容易。组织样品基质的选择和覆盖十分关键,要尽可能的满足组织切片上的蛋白无扩散或移位现象,基质与蛋白形成良好的共结晶,并不是十分容易的事情。然而,美国HTX technologies公司研发的全自动基质喷涂设备让这一切变得简单可行。
HTX公司研发的 全自动MALDI基质喷涂设备(TM-Sprayer)
近期,南卡罗莱纳医科大学-细胞与分子药理学&实验治疗学部发布了一篇基于MALDI
FTMS成像技术的癌变生物标记物N-聚糖的研究。该研究中利用了超高分辨、超高灵敏度的solariX MALDI
FTMS质谱平台,通过对福尔马林固定石蜡包埋(FFPE)组织中的N-聚糖进行质谱成像分析,确定了N-聚糖为组织癌变生物标志物。
实验操作中,在对5µm厚的FFPE甲状腺癌组织切片样品进行酶处理和基质覆盖时均使用了HTX公司的自动喷雾仪产品(TM-Sprayer)来执行,而非传统的手动处理。HTX的这款TM-Sprayer基质喷雾仪最大特点就是能够以精准模式和可调节模式对整个样品区或部分区域进行喷涂,该研究中首先利用TM-Sprayer将浓度为0.1μg/μL的糖苷酶(PNGase
F)喷涂在组织切片表面,37℃环境下孵育。随后,选用基质CHCA进行精确覆盖,确保了细腻、均一稳定的基质涂层。后续获得的MALDI成像结果也显示了较高的信号强度和分辨率。
实验结果
Figure 1. Example N-glycan signal from a single section of thyroid cancer. A Total average spectrum from the image with example glycoform structures per m/z; B Tile view of example images. Inset top right, photomicrograph of unstained tissue prior to imaging. Abbreviations: GlcNAc, N-acetylglucosamine
Figure 2. Image segmentation showing complexity of
N-glycan signatures in a thyroid cancer tissuesection. A Pathologist
marked H&E stain of section highlighting adjacent nontumor,
anaplastic, and necrotic regions. B SCiLS image segmentation of
N-glycans from 2D mapping. White asterisks markcalculated overlaps of
anaplastic and necrotic regions.
Figure 3. Quantification of N-glycan signatures
from regional areas on tissue. Statistical testing was donecomparing
nontumor adjacent and anaplastic regions (ROC-1) or anaplastic versus
necrotic (ROC-2).A Photomicrograph depicting areas selected for
measuring relative abundance of N-glycan expression.B A high mannose
(Man9) structure distinguishing nontumor adjacent compared to anaplastic
tumor ornecrotic regions. C A biantennary N-glycan defining necrotic
regions with low expression in nontumoradjacent and anaplastic. D A
tetrantennary fucosylated structure with low expression in adjacent
nontumor and increasing expression in anaplastic and necrotic tissues
regions.
TM-Sprayer最大的特点就是可以为MALDI质谱成像提供高重现性和高质量数据,该产品已被应用在多个领域的MALDI成像实验中,并有相当数量的科研文献提到应用了该款产品获得优质数据。在质谱成像领域势必将成为MALDI成像的好搭档。