The glass used for microscope slides is specialized optical glass that provides certain important properties:
– Optical clarity and low inclusion – The glass needs to be extremely clear and free of particles/inclusions that can interfere with the passage of light. High optical transmission is required.
– Flatness – Microscope slide glass is made to be very flat and distortion-free. Any waviness or ripples in the glass surface can degrade the specimen image.
– Stable dimensions – To fit microscope stages and objectives, the thickness and dimensions of microscope slides are standardized. Sturdy slides don’t warp over time.
– Low autofluorescence – Fluorescence microscopy requires glass with minimal native fluorescence so it doesn’t interfere with faint fluorescence from the specimen.
– Chemical resistance – The glass needs to resist chemical corrosion from specimen stains, mountants, and cleaning fluids.
– Strength and hardness – Slides withstand repeated handling and cleaning without fracturing or scratching.
The most common glasses used are:
– Soda-lime glass – Economical and offers good optical and mechanical properties.
– Borosilicate glass – Withstands high temps and is more resistant to chemicals/stains.
– Quartz glass – Extremely low in autofluorescence, making it ideal for fluorescence microscopy.
– Fused silica – Very similar to quartz glass with great UV transmission. Used for advanced fluorescence applications.
So specialized optical glasses with strict quality control are required for microscope slides and cover glasses. This ensures high-performance imaging and consistency.
