Quality microscope slides must be in accordance with many international standards. That is why VitroGnost microscope slides are in accordance with such standards as ISO 8037-1:1986, ISO 719, DIN 12 116: class S2 and DIN ISO 695: class A2. Like all other diagnostic reagents used in medical microscopy VitroGnost microscope slides meet the regulations stipulated by the European Commission for in vitro diagnostic devices and CE marking.

CHEMICAL COMPOSITION AND PURITY FOR TOP QUALITY PROPERTIES
Quality of the slide material is the basic requirement for achieving top quality of the slide. The glass must be made of reliable compounds that secure top optical, physical and chemical properties. 

High purity of the material and low amount of iron contribute signifi cantly to top quality optical properties. Low amount of aluminum oxide enhances hardness of the surface and stability of molecular structure of the glass, while high amount of sodium oxide reduces oxidation; that in turn enhances durability. Slides with low amount of iron are white and labeled VitroGnost Super White (SW). Glasses containing higher amounts of iron are slightly green and are typical for other types of VitroGnost glasses that do not bear the SW mark. 

It is extremely important that the slides remain fl at and smooth because that enhances the contact with the tissue section and makes the sample adherence better. Purity level of the slide surface is equally important. Clean and fl at slides demonstrate the Newton’s rings eff ect, similar to oil spilled on sea surface. The eff ect vanishes after slides being touched with fi ngers because even a small amount of “dirt” loosens the contact between the slides. VitroGnost Super Grade slides have extremely clean surface.

Only properly cleaned microscope slides made of high quality glass can remain separated (not adhered), especially if stored without temperature fl uctuations that may cause condensation of humidity and in turn cause the slides to adhere to each other. That is why slides of lower level quality have thin pieces of paper inserted between that prevent adherence (such as VitroGnost Standard or Economy Grade slides).

DIMENSIONS, EDGES AND CORNERS
Dimensions of VitroGnost microscope slides are defi ned by the international ISO 8037/1:1986 standard that allows dimensions ranging from 75.0 to 76.0 mm (length) and 25.0 to 26.0 mm (width). Dimensions of microscope slides are considered to be 76 x 26 mm (approximately 3 x 1 in (76.2 x 25.4 mm)). Slides with cut edges are always a little oversized compared to those with edges because polishing the edges always reduces the edge surface.

Cut edges of glass slides are the simplest type of edges. If not handled with care, they can cause cuts. Ground edges are made by polishing the cut edges, and edges are made with even fi ner polishing of ground slides. The fi nest slides have beveled edges. Cut slides have 90° corners. Ground and slides can have both 90° and 45° corners. The 45° corners require additional processing and are always more expensive than the 90° ones. Their advantages are more pleasant handling, better protection against unwanted laboratory incidents and have better performance while being used with laboratory equipment. All beveled slides have 45° corners.

SURFACE FINISHING
Microscope slides can have specially processed area for entering data. This is achieved by polishing a part of the slide 20 mm wide in order to create a 20 x 26 mm frosted area adequate for entering data using a graphite pencil. Slides can be frosted on one or both sides; that enables adding data regarding the sample. A more modern solution is coloring that part of the slide instead of frosting it. Only white color was being used in the past and in modern times more than 10 colors are used. Colored edges enable easier sorting and labeling (such as VitroGnost Color slides). Graphite pencils were used until recently, as well as special marking pens resistant to solvents or scratching using diamond pens.

The modern age of automatization and informatization brought the necessity for specially applied colors on colored slides in order for purposespecific printers to print the bar code (not only the basic patient and sample data).

VitroGnost slides with colored areas are suitable for thermal transfer printing or for printing using inkjet printers. VitroGnost Color slides marked with TT are suitable for thermal transfer printers (such as Primera Signature Slide Printer), VitroGnost Slides marked with INK are suitable for inkjet printers, while VitroGnost Color slides marked with DP are suitable for printers equipped with diamond pen.

Since there are several companies manufacturing printers that are using diff erent types of ink and thermal transfer ribbons, it is recommended to test print quality of a printer using diff erent settings with diff erent colors on microscope slides. Although TT and INK slides are designed for use with printers, they can be written on using markers and graphite pencils. VitroGnost Color Super Grade slides can also be used with printers after changing the print settings.

ADHESIVE AND WET & DRY ADHESIVE SLIDES
It was mentioned earlier that slide purity and flatness are important for tissue sample adhesion; the greater the surface, the cleaner the slide, and noncovalent attractive forces have a greater eff ect. In order to strengthen those forces, many agents were used, the most frequently used method was applying poly-L lysine and silane in order to apply positive charge to the slide and in turn enhance electrostatic forces toward tissues with negative charge.

That type of slide is called adhesive slide, such as VitroGnost PLL and VitroGnost SIL. Slides with greater positive charge density are VitroGnost Plus Ultra adhesive slides. They are important during processing tissues that are naturally hard to adhere on glass, when there is risk of sample falling off the slide or when applying high temperature during HIER antigen demasking is necessary. All adhesive slides cause the samples to adhere better than regular slides. Because not all tissues adhere on all types of adhesive slides in the same way, the next generation of adhesive slides was developed. Their surface is processed with substances that generate positive charge and those that make the surface either more hydrophobic or hydrophilic. VitroGnost WET & DRY adhesive slides enable choosing an appropriate adhesive slide for every tissue sample regarding the hydrophobic or hydrophilic tissue properties. Those types of slides combine two types of attractive forces; that makes them an optimal choice for compatible tissues.

Adhesive and hydrophilic surface combination (slides such as VitroGnost Plus Wet) is most commonly used with samples with hydrophilic properties, such as frozen sections, cellular suspensions (LBC) and smears, as well as immunohistochemistry equipment.

Adhesive and hydrophobic surface combination (slides such as VitroGnost Plus Dry) is most commonly used with samples with hydrophobic properties,
such as samples embedded in paraffi n, and lipid-rich tissues such as breast, brain, lungs and skin. 

Purpose	DRY Adhesive Hydrophobic	WET Adhesive Hydrophilic
Histopathology
Paraffin samples	***	**
Frozen samples	**	***
Lipid-rich samples	***	**
Immunohistochemistry devices	*/***	***
HIER procedures	***	***
Liquid-based cytology	*/***	***
Microbiology	**	***
Hematology	*	***