SCHOTT NEXTERION^® Thin Glass Substrates for Microarraying and High Resolution Imaging Applications

The standard glass slides that are typically used for microarray and microscope-based applications are usually between 1.0 and 1.1 mm thick. However this is much too thick to image through using high Numerical Aperture (N.A.) objectives that are required by high-resolution microscopic imaging or scanning applications. Most high power microscope objectives are designed for an optimal coverslip thickness of 0.17 mm. In the design of such lenses, the coverslip is included as the final part of the “imaging lens” contributing significantly to the image quality in bright field and fluorescence applications. Using thicker coverslip glass will introduce spherical aberration resulting in a loss of contrast and sharpness in the image. Unfortunately standard No.1½ (175 micron) coverslips have a very wide thickness tolerance range of plus-minus 15 to 20 microns. If the coverslip varies too much from the optimal thickness of 170 nm, it can cause an axial shift of the best focus, and significantly affect; spatial resolution (especially z-axis resolution) in confocal microscopes, contrast of both brightfield and fluorescent specimens, as well as reduced intensity in fluorescent imaging. Other problems with standard commercial coverslips include scratches and digs that create diffraction and stray light, as well as dirt and foreign particles that can directly affect image quality. 
To address these issues SCHOTT offers high-performance "cleaned and inspected" NEXTERION^®coverslips. A special high performance thin borosilicate glass that has a guaranteed thickness variation of less than plus-minus five microns, was developed in collaboration with Carl Zeiss. NEXTERION^® coverslips made with this colorless borosilicate glass are available with, or without functionalised coatings.

The thin glass substrates are manufactured from SCHOTT’s D 263™ M cover glass. This is a colorless low alkali borosilicate glass with a very low iron content. D 263 M meets the requirements laid down in ISO 8255. 
The outstanding features of D 263™ M include:

• High spectral transmission and optically clear
• Excellent internal glass quality with absence of inclusions, striae, bubbles, streaks, etc.
• Excellent flatness and very good surface quality
• Low background fluorescence
• Refractive index of 1.5255 +/- 0.0015 optimized for microscope objectives
• Abbe number of 56 +/- 2
• Excellent resistance to chemical attack (hydrolytic class ISO 719-HGB 1)
• Non-neurotoxic and non-cytotoxic

For high resolution imaging applications, coverslips often have to be hand seleced for the required 170nm thickness to optimize image quality. To avoid this tedious process and to ensure consistent and reproducible image quality, SCHOTT now offers high performance NEXTERION^® coverslips with a thickness of 170 microns +/- 5 microns. These are ISO 8255 compliant Type1½ H as per ISO 8255-1 with restricted thickness-related tolerance.

SCHOTT NEXTERION^® coverslips are available in both “High performance” and “Standard” glass thickness tolerances: 

“High performance” coverslips #1.5H 
Thickness: 170 microns +/- 5 microns
18 x 18 mm coverslips
22 x 22 mm coverslips
24 x 60 mm coverslips
25 x 65 mm coverslips
25 x 75 mm coverslips 

Other dimensions are available to special order

"Standard” coverslips #1.5 
Thickness: 175 microns +/- 15 microns
22 x 22 mm coverslips
24 x 24 mm coverslips
24 x 60 mm coverslips

Other dimensions and standard coverslip glass thicknesses (#0, #1, #2 etc.) are available on request
 

The coverslips are cleaned under class 100 clean room conditions using a highly efficient multi-step, ultrasonic cleaning method, that removes glass debris and surface contaminates. This avoids the time-consuming and cost-intensive procedures normally associated with coverslip preparation. NEXTERION^®coverslips give you more time to get on with your research work.

Standard coverslips are packed surface-to-surface; this often causes scratching of the glass. NEXTERION^®coverslips are cleaned, visually checked and individually packed into custom made packaging.

Special NEXTERION^® packaging

Special developed packaging manufactured from low out-gassing plastic has adjustable holders to separate, and protect cleaned and / or coated coverslips. The convenient package also acts as a storage container preventing particle contamination and damage to the surfaces. The boxes are sealed under an inert atmosphere after cleaning (and coating) to preserve activated surface.

The coverslips can be supplied as uncoated glass that has been cleaned and is ready to use.

Any of the standard NEXTERION^® functional coatings can be applied to coverslip glass in just about any size.
The coatings include: 

• Aminosilane
• Aldehydesilane
• Epoxysilane
• 3-D thin film polymer-NHS ester
• Nitrocellulose

SCHOTT Microarray Solutions is also able to coat glass coverslips with coating chemistries developed by clients. If you cannot find the format or coating you are looking for, please inquire about our NEXTERION^®