Lung tissue samples play a crucial role in several aspects of lung disease research, including drug development, disease diagnosis, and treatment. Preserving these samples properly is essential to ensure their integrity and reliability for downstream analyses.
When it comes to preserving lung biospecimens, there are several options available for researchers and health professionals. In this blog post, we’ll explore 5 of the most effective and commonly used ways to preserve lung tissue samples for research purposes.
-
Formalin Fixation
Source: researchgate.net
Formalin is a widely used fixative that has been the standard for tissue preservation for many years. It works by cross-linking proteins in the tissue, which stabilizes the structure and prevents degradation. Formalin fixation is simple and cost-effective, making it an attractive option for researchers and health professionals. It is also compatible with various downstream methods, including immunohistochemistry and microscopy. The downside of formalin fixation is that it can interfere with DNA and RNA extraction, making it less suitable for molecular studies.
-
Liquid Nitrogen
Liquid nitrogen is a preferred method for freezing and preserving tissue samples for molecular analyses. It rapidly freezes the tissue, which prevents the formation of ice crystals that can damage the tissue. The tissue is then stored at -80°C or lower, which maintains its structural and molecular integrity. This method is ideal for studies that require RNA, DNA, or protein extraction, as it preserves the integrity of these molecules. However, liquid nitrogen storage requires expensive equipment and careful handling to prevent freezer failures and sample contamination.
-
OCT Embedding
Source: en.m.wikipedia.org
Optimal cutting temperature (OCT) embedding is a technique that involves embedding the tissue in a mixture of OCT and cryoprotectant before freezing. This method preserves the morphology and structure of the sample and allows for easy sectioning and handling. OCT-embedded samples are stored at -80°C or lower and are suitable for molecular analyses such as RNA and DNA extraction. The downside of this method is that it can interfere with certain downstream methods, including histology and immunohistochemistry.
-
RNAlater
RNAlater is a commercially available reagent that is ideal for preserving RNA in tissue or cells. It works by permeating the tissue and stabilizing RNA molecules, preventing their degradation. RNAlater is easy to use and can preserve the integrity of RNA for weeks, allowing for transport and storage at room temperature. However, this method is less suitable for other downstream methods, such as protein extraction or histology.
-
Cryosectioning
Cryosectioning involves cutting tissue samples into thin sections using a microtome and mounting them onto slides. This method is ideal for studies that require visualization of tissue morphology, such as histology and immunohistochemistry. The tissue is either frozen or embedded in OCT before cutting, depending on the downstream method. Cryosectioning requires special equipment and expertise, but it is a widely used technique in research and diagnostics.
How to Use Lung Tissue Samples for Research
Next, we take a look at how to use lung tissue samples for your research purposes. Let’s get into it!
Obtaining Lung Tissue Samples
The first step in utilizing lung tissue samples for research is to obtain them. Different methods of sample collection are available, depending on the research question and the nature of the tissue required. Common approaches include bronchoscopy, transthoracic needle biopsy, and surgical resection. It is essential to follow strict ethical guidelines and obtain informed consent from donors and their families for the collection of lung tissue samples.
Processing and Preservation
Once the samples are obtained, they need to be processed and preserved properly to minimize degradation and ensure the integrity of the biological material. The handling and storage conditions depend on the intended application of the tissue. For example, if the samples are intended for gene expression analysis, the RNA must be protected from degradation by RNase enzymes. Similarly, if the samples are prepared for histology analysis, the preservation method should maintain the tissue’s structural integrity.
Analyzing Lung Tissues
The choice of analytical techniques depends on the research question and the type of tissue sample. Several methods are available, ranging from basic histology and immunohistochemistry to advanced genomic and proteomic analyses. The latest technologies include single-cell sequencing, spatial transcriptomics, and imaging mass spectrometry. These approaches enable researchers to explore the cellular and molecular diversity of lung tissues and identify key biomarkers and therapeutic targets.
Quality Control and Standardization
To ensure the reliability and reproducibility of research findings, it is crucial to adhere to rigorous quality control and standardization protocols. These include using standardized protocols for sample collection, processing, and analysis, monitoring the performance of analytical platforms, and establishing strict criteria for data interpretation and reporting. The development of quality control standards and reference materials for lung tissue analysis is an ongoing effort aimed at enhancing the robustness and comparability of research outcomes.
Future Perspectives
The use of lung tissue samples for research purposes has enormous potential to advance our understanding of lung biology, disease pathogenesis, and therapeutic interventions. As research technologies and methodologies continue to evolve, new opportunities and challenges will emerge. Future directions include the integration of multi-omic approaches, the development of organoid and 3D printing models, and the exploration of non-invasive sampling techniques, such as liquid biopsies. The translation of research findings into clinical applications also remains a critical area of focus.
How Will You Preserve Lung Tissue Samples?
Preserving and utilizing lung tissue samples can be challenging, but several effective and widely used methods are available for researchers and health professionals. Choosing the right method depends on the research question, downstream analysis, and available resources. Formalin fixation, liquid nitrogen, OCT embedding, RNAlater, and cryosectioning are some of the most commonly used ways to preserve lung biospecimens. Whichever method you choose, it is crucial to handle and store the samples carefully to ensure their integrity and reliability for downstream studies.
The use of lung tissue samples for research purposes offers an exciting avenue for scientific inquiry and clinical translation. This approach requires careful attention to ethical, technical, and analytical factors to ensure the quality and accuracy of research findings. By following the latest techniques and best practices for using lung tissue samples, researchers, laboratories, scientists, and health professionals can contribute to advancing lung disease research and improving patient outcomes.