TissueGrinder: Improved cell analyses via enhanced-quality sample preparation

A new method for examining tissue samples could change the way we diagnose and treat cancer. Researchers at the Max Planck and Fraunhofer IPA have developed an automated system based on the principle of enzyme-free tissue processing and the mechanical deformability of individual cells.

The system enables the fast and precise identification of tumor cells in tissue samples without the need for additional markers. In an interview with MEDICA-tradefair.com, Stefan Scheuermann explains the individual steps of the analysis procedure.

Mr. Scheuermann, the analysis procedure is based on several steps, starting with a new method of preparing the tissue samples. How exactly does this work?

Stefan Scheuermann: In many research institutions and clinics, tissue samples are still cut up manually with scalpels and tweezers or treated with enzymes, which can lead to disadvantages such as a lack of reproducibility and non-specific enzyme treatment. This in turn has a major impact on the results of subsequent analyses of the individual cells.

We have developed a technological solution, the TissueGrinder, to isolate single cells from these tissue samples efficiently and enzyme-free and to minimize the limiting factors of sample preparation.

The TissueGrinder is a semi-automated system that prepares the sample in a standardized way, which is also possible without the use of enzymes. As a result, the sample is processed quickly and gently into individual cells and is available for analysis.

The aim of this process is to preserve the individual cells in their native state as far as possible in order to obtain representative results. Of course, the sample is altered by the process outside the body, but the technology aims to minimize these changes and provide better insights into what is happening in the body.

The tissue grinder is already in use. The subsequent system for analyzing the samples is new. How does it work?

Scheuermann: The RT-DC system, or real-time deformability cytometry, uses a technology that was developed by the Max Planck Institute. It uses a microfluidic chip on which the cells of a tissue sample are analyzed individually. As the cells flow through a narrow channel, they are deformed and their mechanical and morphological properties are analyzed.

With the help of image analysis tools, users can then classify the cells and distinguish not only their size and appearance but also their deformability, among other things. This can be a decisive difference between a tumor cell and the corresponding healthy cell.

One advantage of this method is that the cells do not have to be specially labeled in advance. However, this analysis method generates a great deal of data, which is processed with the help of intelligent algorithms.

This is certainly no substitute for a sound diagnosis. But how can this approach help with the analysis?

Scheuermann: No, the algorithm does not make a diagnosis. But it helps to differentiate: Is it a tumor cell or another cell type? This is achieved through the automated recording and evaluation of a large number of cells. It is therefore a matter of examining the huge amount of data and using the right parameters to highlight various pieces of information.

This information is intended to support and supplement pathological diagnoses in the future. This workflow is currently still in the research phase and is not yet being used in a clinical environment.

The field of application of this procedure is not limited to cancer. In which direction is research still heading?

Scheuermann: The TissueGrinder is primarily about dividing solid tissue into individual cells and improving and standardizing sample preparation processes. Once divided, a wide range of analyses can be carried out. Cancer is undoubtedly one of the main areas, but we are also active in other areas where the isolation of single cells and their analysis is required.

The TissueGrinder technology is characterized in particular by the improvement in sample preparation, which makes it interesting for many different areas of application. One example of this is 3D cell culture. On the one hand, this involves cultivating the isolated cells, and on the other, direct analysis. In addition, it is possible to examine the cells molecularly at the single cell level and thus obtain detailed information about the processes within a cell.

Our approach to ensure that the quality of the starting material is crucial. It is often said "garbage in, garbage out", which means that the quality of the analysis strongly depends on the quality of the starting samples. Therefore, we strive to develop and offer a reproducible and standardized method that minimizes quality loss from the start.