Poly-D-Lysine Coated Culture Dishes: Long-Term Support for Neuronal Cultures
Not all mammalian cell types are simple to grow and maintain in cultures. Some cell types, e.g., NIH 3T3 cells, adhere onto tissue culture plastics easily and has fast doubling time. Some cell types, e.g., neurons are relatively difficult to grow in cultures since these cells tend to adhere poorly onto untreated surfaces and have slower doubling time. These neurons are highly sensitive, anchorage-dependent cells and often need more than a standard culture surface to survive, attach, and develop healthy and normal structural extensions. That’s why many neuroscientists rely on poly-D-lysine (PDL), a synthetic coating that provides stable, long-term support for these neuronal cells.
PDL creates a positively charged surface that promotes robust adhesion of cells with low natural affinity to glass or plastic. Unlike its close cousin poly-L-lysine (PLL), PDL is resistant to enzymatic degradation, making it the preferred choice for long-term or extended culture protocols. With WPI’s 35 mm PDL coated FluoroDish™ glass-bottom culture dishes with 23 mm glass bottom, researchers can get the best of both worlds: a durable and coated surface for delicate cells and a glass-bottom dish optimized for high-resolution and fluorescence-based imaging.
What Is Poly-D-Lysine?
PDL is a synthetic polymer made from the D-enantiomer of lysine, an amino acid. It does not occur naturally in biological systems, which is precisely what makes it so valuable. While poly-L-lysine (made from the L-form) can be broken down by cell-secreted proteases over time, PDL resists enzymatic degradation, offering greater longevity in culture.
The PDL coating favors neuronal cell adhesion by favoring electrostatic interaction. The positively charged lysine residues attract the negatively charged components of the cell membrane, anchoring cells to the dish surface without the need for coating of extracellular matrix (ECM) proteins.
Why Use PDL in Cell Culture?
PDL is particularly useful when working with Primary neurons (such as, hippocampal, cortical), glial cells and astrocytes, hybridoma and other weakly adherent cell lines, and neurospheres or neural precursor cells. Because these cells do not readily attach to untreated plastic or glass, PDL provides the secure substrate needed for neurite outgrowth and branching, and synapse formation. The formation of normal cellular structures and extensions are crucial for electrophysiology studies and extended time-lapse imaging or long-term assays.
PDL vs. PLL: What’s the Difference?
While both PDL and PLL are lysine-based polymers that are known to enhance cellular adhesion, there are key distinctions. PDL offers better stability and is less likely to degrade, making it ideal for prolonged experiments, more effective especially with sensitive or slow-growing cells.
| Feature | PDL | PLL |
| Enantiomer Form | D-lysine (non-natural) | L-lysine (natural) |
| Enzyme Resistance | Yes – stable long term | No – may degrade over time |
| Cost | Slightly higher | Lower |
| Ideal Use Case | Long-term neuronal cultures | Short-term imaging/transfection |
Why Pair PDL with FluoroDish™?
High quality imaging is desirable with neuronal studies. WPI’s glass-bottom FluoroDish™ provides a stable and optically pure platform to visualize slow growing, sensitive cells over time:
- No autofluorescence from the dish bottom ensures clean, crisp fluorescence microscopy.
- Coverslip-thin glass allows for fast, even heat transfer, ideal for warming plates or environmental chambers integrated with microscopy set up or while growing cultures inside the incubator.
- 35 mm format provides ample space for neurons to extend processes while remaining compatible with upright and inverted microscopes.
PDL coated FluoroDish™ favors cellular growth of slow growing sensitive cells and lets you save time and resources to generate valuable and consistent data in which you can have high confidence.
Applications in Research
PDL-coated FluoroDishes™ are trusted tools in:
- Neuroscience: Axon guidance, synaptogenesis, and calcium imaging
- Developmental biology: Early neural differentiation from stem cells
- Electrophysiology: Patch-clamp and multielectrode array studies
- Cellular toxicology: Drug or compound screening in neural models
When to Choose PDL
Choose PDL when you are working with cells prone to detachment or apoptosis, running multi-day experiments that require stable adhesion, performing high-resolution or fluorescence imaging, or culturing primary neurons or glial cells from brain/spinal cord tissue.
Available Configurations
PDL coatings are available on 35 mm FluoroDish™ cell culture dishes with 23 mm glass bottom, making them ideal for neuronal studies that involves high-quality imaging and experimental control.
Up Next: Poly-L-Lysine—Versatile, Reliable, and Cost-Effective
In our next post, we’ll compare PDL’s close cousin: poly-L-lysine (PLL). While not as stable, PLL remains a popular choice for short-term experiments, fixed-cell imaging, and budget-conscious labs looking to improve adhesion across a wide variety of cell types.
