Gene expression profiling is a crucial technique in molecular biology that allows researchers to analyze the activity levels of thousands of genes simultaneously. This information can provide valuable insights into cellular processes, disease mechanisms, and the effects of treatments. To conduct effective gene expression profiling, several steps are involved, particularly when utilizing advanced technologies like the FFPE Transcriptomics Solution from STOmics. This article will guide you through the essential steps involved in this process.

Sample Preparation

The first and foremost step in gene expression profiling is the preparation of your samples. For optimal results, high-quality RNA is essential. In the context of using the FFPE Transcriptomics Solution, you will begin with formalin-fixed paraffin-embedded (FFPE) samples, which are commonly used in clinical and research settings due to their long-term stability.

To prepare the samples, carefully deparaffinize and rehydrate the FFPE tissues. This usually involves treating the samples with xylene and then a series of alcohol washes. Following rehydration, perform RNA extraction using a suitable kit that can efficiently isolate high-quality RNA, even from challenging FFPE samples. The quality and integrity of the RNA can then be assessed using a spectrophotometer or a bioanalyzer, ensuring that it meets the criteria for downstream applications.

Stain and Image

Once the RNA is prepared, the next step involves staining the tissue sections for histological analysis. Using histological stains, researchers can visualize the morphology of the tissues and the specific areas of interest within them.

After staining, imaging the tissue is critical for spatially referencing the RNA later in the process. Advanced imaging techniques such as brightfield or fluorescent microscopy can be used, depending on the specific requirements of your study. Captured images will serve as the basis for correlating gene expression data with histological features when analyzing results later on.

RNA Capture & cDNA Synthesis

Following imaging, the next step is to capture the RNA from the tissue. The FFPE Transcriptomics Solution allows for in situ RNA capture, which means that the RNA is collected directly from the tissue sections where it is expressed. This step is key in preserving spatial information.

Once the RNA is captured, the next step is cDNA synthesis. In this process, the RNA is reverse transcribed into complementary DNA (cDNA), providing a more stable form of the transcript for subsequent analysis. Ensuring that this process is robust and efficient is critical for obtaining reliable results in the following stages.

Library Construction and Sequencing

After cDNA synthesis, the next step is library construction. This involves preparing DNA libraries that are compatible with sequencing technologies. The libraries are constructed by adding sequencing adapters to the cDNA.

For sequencing, the Stereo-seq libraries can be processed on either the DNBSEQ-T7RS or DNBSEQ-G400RS platforms utilizing the PE75 Stereo-seq Visualization Reagent set. This step generates the raw sequencing data needed for analysis.

Data Analysis & Visualization

The final step in gene expression profiling is data analysis and visualization. After sequencing, the data should be processed using the Stereo-seq Analysis Workflow (SAW). This consists of Linux command-line-based pipelines that help map the sequenced reads back to their spatial locations on the tissue section.

Once the data is mapped, the results can be interactively displayed using the StereoMap visualization software, which is compatible with both Windows and MacOS. This software allows researchers to visualize the spatial distribution of gene expression patterns within the tissue, facilitating deeper insights into the functional dynamics of the studied biological system.

Unlocking Insights Through Gene Expression Profiling

In summary, gene expression profiling is a multi-step process that provides valuable insights into biological systems, particularly when utilizing innovative technologies like the FFPE Transcriptomics Solution by STOmics. By following the steps from sample preparation through data analysis, researchers can obtain meaningful data that enhances our understanding of cellular processes and disease mechanisms. The comprehensive approach offered by the FFPE Transcriptomics Solution simplifies complex workflows, making it an essential tool for modern research in spatial transcriptomics.