What is DPX?
DPX is a resin-based mounting medium commonly used in histology. It is employed to preserve and protect
microscope slides after the
staining process, ensuring that the
specimen remains intact and visible under the microscope for an extended period.
Composition of DPX
DPX is primarily composed of
distyrene (a polystyrene), a plasticizer (tricresyl phosphate), and xylene. The combination of these components provides a clear, durable medium that enhances the clarity of stained tissue sections.
Why Use DPX?
DPX is favored in histology for several reasons: Clarity: DPX offers excellent optical clarity, making it easier to observe fine details in tissue sections.
Durability: Once dried, DPX forms a hard, stable layer that protects the specimen from physical damage and environmental factors.
Compatibility: DPX is compatible with a wide range of
histological stains, including hematoxylin and eosin (H&E).
How to Use DPX?
Applying DPX involves a few crucial steps: Preparation: Ensure that the stained tissue section is thoroughly dehydrated, usually through a series of graded alcohols followed by xylene.
Application: Place a small drop of DPX on the specimen and gently lower a coverslip onto it to avoid air bubbles.
Drying: Allow the slide to dry completely, which can take several hours to overnight, depending on the thickness of the DPX layer.
Advantages and Disadvantages
While DPX is widely used, it has its pros and cons: Advantages: It provides long-term preservation, excellent optical properties, and is relatively easy to use.
Disadvantages: The use of xylene, a component of DPX, poses health risks due to its toxicity and flammability. Proper ventilation and safety measures are essential.
Alternatives to DPX
Although DPX is popular, alternatives exist, such as
Canada balsam and synthetic resins like
Entellan. These alternatives may offer different advantages, such as reduced toxicity or faster drying times.
Storage and Handling
Proper storage and handling of DPX are critical: Storage: Store DPX in a cool, dry place away from direct sunlight and sources of ignition.
Handling: Use in a well-ventilated area, and wear appropriate personal protective equipment, such as gloves and safety glasses.
Conclusion
In the realm of histology, DPX stands as a reliable and effective mounting medium. Its ability to preserve stained specimens with high clarity makes it a staple in laboratories. However, users must be mindful of the associated health risks and take necessary precautions during its application. Understanding the properties and proper usage of DPX ensures the longevity and quality of histological preparations.
