Tissue culture is the process of maintaining cells in vitro. Cells are routinely kept in suspension, adhering to the surface of a vessel, or as 3D culture systems (e.g., spheroids and organoids). Their use as model systems is integral to life science research and requires regular use of a light microscope for assessing confluency (percentage of the vessel area covered by cells), cell counting, monitoring for pathogens, and morphological assessment.
Products for Tissue Culture
The Nikon ECLIPSE Ts2 and Ts2-FL inverted microscopes are award-winning systems designed for routine tissue culture-related work. The Ts2-FL has all the features of the Ts2 but additionally provides built-in LED-based epifluorescence.
●: included, ⚬: option
|Camera Integration||Free Selection (optional)||Free Selection (optional)|
|Accommodates well plates, dishes, and flasks||yes||yes|
|Compatible Contrasting Techniques||ECLIPSE Ts2||ECLIPSE Ts2-FL|
|Nikon Emboss Contrast||yes||yes|
|Apodized Phase Contrast||yes||yes|
Discussion of Tissue Culture
Contrasting techniques for tissue culture
A wide variety of cell types are cultured in vitro, including primary cells recently obtained from tissue, immortalized cell lines, and stem cells. These different types of cells present similar imaging challenges.
An obstacle to seeing cells is their generally high degree of transparency, which restricts the usefulness of standard brightfield transmitted light microscopy. For this reason, tissue culture microscopes are often equipped for phase contrast imaging – a technique that uses interference to translate subtle differences in optical path length into contrast (even in mostly transparent specimens). Importantly, phase contrast is compatible with plastic culture vessels, unlike polarization-dependent techniques such as differential interference contrast (DIC).
Phase contrast makes identification of single cells relatively easy compared to brightfield, even at low magnification (objective lenses with a magnification between 4 – 20X are most often used for tissue culture). However, phase contrast imaging requires specialized objective lenses and a corresponding annular mask in the illumination light path. Furthermore, there are various types of phase contrast objectives to choose from.
Nikon’s CFI Achromat Series for Apodized Phase Contrast objective lenses are useful for tissue culture observation thanks to the provided reduction in the halo artifact that arises in areas with large optical path differences. This makes it easier to identify the borders of cells and to accurately observe larger model systems, such as tissues and whole organisms, compared to standard phase contrast objectives.
Fluorescence imaging and tissue culture
Fluorescence imaging is becoming a more-and-more routine requirement in the tissue culture laboratory. For example, a common task is checking the expression of fluorescent protein fusions by transfected cells – important for evaluating transfection efficiency, proper localization, and expression levels. Fluorescent stains are also widely used for visualizing key subcellular components (e.g. Hoechst dyes for staining nuclei in live cells).
The ECLIPSE Ts2-FL features up to three different user-selectable LED illumination modules which are built into the microscope. The microscope automatically remembers which LED to use for each filter cube position, and the last used brightness setting. Nikon also offers an optional Contrast Shield accessory for helping to block background ambient light, which is frequently a problem in brightly-lit culture rooms.
The importance of size and comfort
Tissue culture work is often repetitive, resulting in a need for an ergonomically correct system that prioritizes ease of use and economy of motion. The ECLIPSE Ts2 controls are grouped in zones depending on if they are used for transmitted light illumination (left side of the microscope), epifluorescence (right), or both (center).
Tissue culture microscopes are often placed inside biosafety cabinets in order to promote a sterile environment and help protect cell health. Thus, a compact microscope can be advantageous for such work. Additionally, the stage is positioned low on the body, making repeated sample exchange more ergonomic to perform from a sitting position compared to microscopes with stages that are positioned higher up on the body.
Nikon microscope products for regenerative medicine
If you’re interested in Nikon microscope products for the development of cell-based therapies for replacing/repairing/treating diseased or injured tissues and organs, we invite you to visit our solutions article on Nikon microscope products for regenerative medicine.
- Accommodates well plates, dishes, and flasks
- These are the common types of vessels used for culturing cells. This category refers to the availability of Nikon stages/inserts for standard size vessels.
- Apodized Phase Contrast
- Apodized phase contrast is a variation of the technique optimized for observing areas with strong phase objects, such as chromosomes in a mitotic cell. It is also useful for observing tissue slices.
- Camera Integration
- Nikon manufactures and distributes a variety of cameras well suited to tissue culture related tasks.
- Compatible with decontamination using vaporized H2O2
- Vaporized hydrogen peroxide decontamination is an industry standard for enclosed spaces. It is widely applied in hospitals and medical research facilities.
- Nikon Emboss Contrast
- Nikon’s Emboss Contrast is a simple technique for observing cells with 3D-like relief. This technique is intended for thick cell types, such as oocytes and induced pluripotent stem cells (iPSCs).
- Phase Contrast
- Phase contrast microscopy is the long-time laboratory standard for observation of adherent cells with fibroblastic or epithelial-like morphology. This includes MDCK, HeLa, HEK, and many other common cell lines.
- Suitable for cell manufacturing facilities
- This refers to whether systems are capable of performing common types of assays applied in cell manufacturing facilities (e.g. stem cell colony identification).
- Suitable for standardized results
- This refers to the combination of whole vessel imaging and analysis for accurate quantification of key parameters in a manner that minimizes the potential of error due to factors such as operator judgment and insufficient sample size.
- Widefield Fluorescence
- Fluorescence microscopy is needed for observing cell components labeled with fluorescent proteins or fluorescent stains.