发布: 2020年02月05日第10卷第3期 DOI: 10.21769/BioProtoc.3510 浏览次数: 4178
评审: Imre GáspárNidhi SharmaShalini Low-Nam
Abstract
Visualization of RNA molecules in situ helps to better understand the functions of expressed genes. Currently, most conventional in situ hybridization methods for visualization of individual RNAs are based on fluorescence detection. Herein we present a chromogenic in situ hybridization protocol for visualization of single RNA molecules in fixed cells and tissues. The protocol is based on padlock probing and rolling circle amplification to generate detectable chromogenic signal from single RNA molecules. Chromogenic signal can avoid background autofluorescence and can be preserved for a longer period than fluorescence signal.
Keywords: Chromogenic in situ hybridization (显色原位杂交)Background
The abundance and spatial location of expressed RNA molecules indicates the physiological and pathological status of cells and tissues. Therefore, there is an increasing interest for in situ RNA detection. Compared to conventional in situ hybridization methods, novel methods that can detect RNA at individual molecule level are more sensitive and specific (Crosetto et al., 2015). These methods include single molecule fluorescence in situ hybridization (smFISH) (Femino et al., 1998), methods based on rolling circle amplification (Larsson et al., 2010), hybridization chain reaction (HCR) (Shah et al., 2016), and branched DNA (bDNA) technology (Wang et al., 2012; Battich et al., 2013). Current methods for individual RNA in situ detection assays are normally readout as fluorescence signal, which offers good sensitivity and is easy to multiplex. Chromogenic readout is often used in conventional RNA ISH assays, providing stable signal that can be stored for long period of time, and is not affected by autofluorescence or photobleaching. Therefore, we introduce the single molecule chromogenic in situ hybridization (smCISH) assay that enables sensitive and specific detection of individual RNA in fixed cells and tissues (Jiang et al., 2019). Our protocol is based on padlock probing and rolling circle amplification (Nilsson et al., 1994; Banér et al., 1998). First, padlock probe is designed to directly bind to target RNA specifically. After padlock probe hybridization, probe circularization is performed using SplintR DNA ligase. The closed circle is RNA-templated ligation of its two ends. Next, an RCA primer is hybridized to the circularized padlock probe to initiate rolling circle amplification reaction. The padlock probe is then amplified into its complementary concatenated form to generate RCP. HRP labeled detection probes are then hybridized to the RCP. Finally, chromogenic signal is developed using H2O2 and 3,3'-Diaminobenzidine (DAB) to generate brown insoluble dots from individual RCPs, which corresponds to single RNA molecules. Our results show that single molecule chromogenic in situ hybridization assay can count and localize individual RNA molecules in fixed cells and tissue samples.
Materials and Reagents
Equipment
Software
Procedure
文章信息
版权信息
© 2020 The Authors; exclusive licensee Bio-protocol LLC.
如何引用
Jiang, M., Lin, C. and Ke, R. (2020). Detection of Individual RNA in Fixed Cells and Tissues by Chromogenic ISH. Bio-protocol 10(3): e3510. DOI: 10.21769/BioProtoc.3510.
分类
癌症生物学 > 通用技术 > 生物化学试验
细胞生物学 > 细胞成像 > 共聚焦显微镜
分子生物学 > RNA > RNA 标记
您对这篇实验方法有问题吗?
在此处发布您的问题,我们将邀请本文作者来回答。同时,我们会将您的问题发布到Bio-protocol Exchange,以便寻求社区成员的帮助。
提问指南
+ 问题描述
写下详细的问题描述,包括所有有助于他人回答您问题的信息(例如实验过程、条件和相关图像等)。
Share
Bluesky
X
Copy link