Best Practices for Sample Preparation in Cell Imaging

Cell imaging is a widely used technique in cell biology to study cells and their internal structures. A crucial part of cell imaging is sample preparation, as this method can significantly impact the accuracy and reliability of the obtained data during an experiment. In this blog post, we will examine the best practices for sample preparation in cell imaging and discuss other aspects of experiments that researchers should consider to ensure optimal results.

Understanding Cell Imaging

Before discussing sample preparation in detail, it is important to understand some of the different cell imaging techniques available to researchers. A commonly used method is fluorescence microscopy, which uses fluorescent probes to visualize specific cellular components. Another favored technique is confocal microscopy, as this enables high-resolution imaging by eliminating out-of-focus light. These techniques both require high-quality, well-prepared samples for researchers to obtain accurate images and extract meaningful data.

Sample Collection and Handling

Cell culture methods play a significant role in the sample preparation of cell imaging. There are several reasons for this, but primarily healthy and viable cells are required for microscopy experiments to be successful. This involves a process called cell passaging, during which cells are regularly transferred to new culture vessels to maintain healthy cell growth in a controlled environment. 

Secondly, using the correct media formulation during sample preparation is vital. The right formula should give cells the nutrients they need to grow and develop a suitable environment. This helps researchers obtain high-quality, accurate images that can be analyzed effectively.

Additionally, researchers must regularly monitor cells for attachment, confluency, nutrient supply, and signs of contamination, as preventing cell degradation and maintaining integrity is necessary for healthy, reliable cells.1

Sample Preparation Techniques

For effective cell imaging, cell fixation is a critical step in sample preparation. This involves using an appropriate fixative agent to help maintain cellular structure during experiments, but each fixative depends on the specific requirements of the experiment. A fixative enables researchers to use selected antibodies and dyes on cells to study their morphology and structure.2

Different fixatives have various effects on cellular structures, and common agents include formaldehyde or methanol. Sample permeabilization is also required to support antibody penetration and enhance staining efficiency. To ensure staining is accurate, blocking and antigen retrieval techniques are employed to prevent non-specific binding. Additionally, immunostaining involves the use of primary and secondary antibodies and requires careful selection of concentrations and incubation times. Finally, selecting the right mounting substance is crucial for preserving samples and minimizing photobleaching during imaging.

Quality Control and Troubleshooting

Quality control measures should be implemented during sample preparation to ensure accurate imaging results. Protocols should be regularly validated and optimized to help monitor potential issues and ensure consistency. Common issues in cell imaging, such as sample contamination and improper fixation, can promptly be resolved through the right troubleshooting techniques. Additionally, employing validation techniques, such as positive and negative controls, aids in verifying the accuracy and reliability of the imaging process.

Advanced Techniques and Considerations

There are additional considerations for obtaining optimal results when employing advanced cell imaging techniques.

    • Super-resolution imaging is used to study delicate cell structures that are not ordinarily visible but require meticulous sample preparation to preserve them.

    • Live-cell imaging is used to study dynamic cellular processes over longer periods of time but requires special considerations to maintain sample viability.3

    • Multi-color imaging poses challenges related to spectral overlap, necessitating strategies to optimize fluorophore selection and minimize cross-talk between channels.

It is also essential to choose stains, probes, and methods that do not compromise cell health and maintain experiment reliability. 

Tips for Efficient and Time-Saving Sample Preparation

Efficient sample preparation requires streamlined methods and reducing unnecessary steps. One option is automation: Automating specific processes using liquid handlers and robotics can significantly reduce the time and effort required.

Maintaining accurate records of sample preparation methods, including incubation times, reagents, and other details, is also crucial. This ensures consistency and facilitates future reference and repeatability. By implementing these tips, researchers can optimize their workflow and enhance efficiency in sample preparation practices.

Automating Cell Imaging with IDEA Bio-Medical

Sample preparation is vital for obtaining high-quality and reliable cell imaging results. Researchers can ensure optimal imaging conditions and preserve cell integrity by following best practices in sample collection and considering the most appropriate methods for collection, handling, fixation, and other processes. 

As we briefly mentioned, employing automation is one method of enhancing cell imaging methods as it improves workflow, enables higher throughput, and maintains high levels of imaging accuracy. 

Systems such as the Hermes 24/7 imaging system by IDEA Bio-Medical were engineered to automate sample preparation, enabling researchers to focus fully on analyzing their results. The Hermes 24/7 requires minimal space and enables laboratories to expand their capabilities while maintaining flexibility and precision in sample positioning. 

Contact a member of IDEA Bio-Medical today to learn more about the importance of sample preparation in cell imaging.