What tissue format are available for your experiments?

When it comes to conducting experiments in biomedical research, choosing the right tissue format can be crucial to obtaining reliable and relevant results.

There are several types of tissue formats used in research and each with their own advantages and considerations. Below, we will explore the main different tissue formats, such as FFPE blocks, fresh tissue, frozen tissue, and tissue slides, to help you determine the format that best fits with your experiments.

Human tissue formats for research purposes

Human tissue samples are collected from a specific organ and can be obtained from living donors or deceased donors (as part of disease diagnosis, treatment, or surgery). This can be tissue procurement from surgical biopsies, removed tumours, organs discarded for transplantation and blood transfusions.

Here is a list of the main tissue sample types that are used in research:

• Fresh Tissue: Fresh tissue is collected and processed without any form of chemical fixation. This format is preferred for experiments that require the extraction of intact nucleic acids and proteins, such as DNA or RNA sequencing and protein analysis using immunohistochemical techniques. Fresh tissue offers the advantage of preserving the original characteristics and biological activity but requires rapid handling and processing to avoid tissue degradation.
• Frozen tissue: Frozen tissue is stored at very low temperatures to preserve its viability and biological characteristics. This format is useful for studies that require the preservation of proteins and nucleic acids in their native state. Quick freezing and proper storage are crucial to maintaining the integrity of frozen samples.
• FFPE (Fixed Tissue) blocks: FFPE blocks are a common way to preserve tissue for later analysis. The tissue is fixed in formalin and embedded in paraffin for long-term preservation. This format is ideal for retrospective studies and allows biomarker analysis in archived tissues. FFPE blocks are especially useful for research that requires a large number of samples and associated clinical data.
• Tissue Slides: Tissue slides contain thin sections of tissue fixed and mounted on glass slides. This format is widely used for histopathological studies and microscopic analyses. The slides allow a visual evaluation of the morphological and cellular characteristics of the tissue, which is essential for the diagnosis of diseases and the identification of pathological changes.
• OCT (Optimal Cutting Temperature): It is a tissue format used to freeze and preserve fresh samples. It consists of a cryoprotective solution that freezes quickly, preserving the structure and characteristics of the tissue. Frozen OCT samples are cut into thin sections for microscopic analysis. The OCT allows to preserve the histological characteristics and protects against damage during freezing, being versatile for different analysis techniques.
• RNA-LATER: This solution widely used in research involving the preservation of RNA (ribonucleic acid) samples. It is used to stabilize and protect the RNA present in the tissue, preventing its degradation and guaranteeing the integrity of the transcripts.

An important advantage of BeCytes Biotechnologies regarding the mentioned tissue formats is the possibility of creating “matched sets” or sets of paired samples by creating custom projects. This means that tissue samples of different formats (eg FFPE blocks, fresh and frozen tissue) can be collected from the same patient or biological sample, allowing comparative analysis and correlation of results between different formats.Creating sets of paired samples is especially useful in longitudinal or follow-up studies, where samples are collected at different points in time. For example, fresh tissue samples may be obtained during an initial surgery and then frozen tissue samples may be collected at subsequent follow-up visits.

This strategy makes it possible to assess changes over time and better understand the progression of a disease or the response to a treatment.
In addition, paired sample sets can also help to minimize individual variation and bias in analysis, as samples from the same individual or group are compared. This increases the validity and reliability of the results, allowing for a more accurate and robust interpretation of the data.