When it comes to wet slides, tiny bubbles are problematic. Bubbles or water drops create problems for the observer. The air bubbles have a different refractive index than water, making the bubble appear darker and thicker in the microscope lens.
Air bubbles can be ignored and do not create problems if the specimen you observe is more prominent in size but you should remove the air bubble for precise results if the sample size is minimal.
Why are there Air Bubbles on the Slide?
An air bubble is formed through the observer’s negligence, and occasionally, slides need an experienced person to handle.
These are the two significant reasons for air bubble formation in the slide
- Bubbles will occur if the setup media is agitated or vortex vigorously.
- The sample can be encased in air. When you apply the coverslip, the air is compelled into the mountant over the sections. That is why you do not be aware of any bubbles till after you have set up. It’s viable that the buffer could probably keep air.
How to Make Slides free of Air Bubbles?
Try setting the slide cover on one edge and lowering it onto the slide. Incorrect positioning of the slide may also result in air bubbles. It is fine to slightly round the slide to prevent air from gathering below the slide cover.
For good results, follow these steps:
- The specimen should be positioned in a vacuum chamber and pumped down. These are then stored in an airtight bag in the freezer with a desiccant percent while they’re now no longer in use to prevent bubbles.
- During the staining phase (the BSA blocking step), remove the sections from the vacuum and place them back in for some other 45 minutes.
- The vacuum phase may need to be moved to the final wash earlier than mounting, or more vacuum steps may also want to be delivered if troubles persist.
How to Remove Air Bubbles?
- Good Slides: Always use good quality slides.
- The position of the coverslip: At a mild angle, place the coverslip over the water droplet. On the other hand, this allows the passage of air.
- The positioning of water: Before lowering the coverslip, if the specimen isn’t completely submerged in the water droplet, Add a drop of water on the specimen carefully so that it completely submerged in water.
- Use a material other than water to mount your slide: There are numerous alternatives for mounting: immersion oil, nails, and Euparal. Hydrophobic specimens may also interact higher with those mediums considering they’re much less likely to be dissolved through water (along with bird feathers, fur, etc.).
- Let go of the surface tension: Add a small amount of detergent, along with soap, and mix. This process will disrupt the water’s surface tension. As a result, bubbles may be avoided from forming on a few specimens. The soap can potentially damage water creatures.
- Apply a vacuum cleaner: Place the type of slide in a vacuum to take away air bubbles. The air bubbles will lift up to the surface of the cover glass, in which they may be visible. Remove moisture from the specimen by immersing the specimen in alcohol. They may also shrink and lose water and air in a few cases.
- Eliminate fats and grease: Rinse the specimen with a solution of ethanol. The specimen becomes much less hydrophobic because of this. When the water is starting to dry out, air bubbles may also appear. Water can be delivered from the cover glass if an air bubble extends to its outside edge.