Histology

We offer the histotechnologist a broad range of quality products to do his work. Solvents, fixatives or embedding media, have been in our program for years. Now, we also offer stains in solution to complete our range.

FIXATIVES

Formaldehyde is the most widely used fixing agent in pathoanatomy. To prevent excesive acidity due to hypoxia of tissues it is important that formaldehyde is buffered at neutral pH.
We provide several products of different concentration and quality.

DESCRIPTION	CAT. NO.
Formaldehyde 3,5-4%, buffered pH7, stabilized	FO0013
Formaldehyde 10%, buffered pH7, stabilized	FO0014
Formaldehyde 35%, synthesis grade	FO0009
Formaldehyde 37%, extra pure Ph Eur USP	FO0010
Formaldehyde 37%, r.g. ACS ISO	FO0011

Glutaraldehyde is recommended for fixation of tissues for electron microscopy. We provide two different concentrations.

DESCRIPTION	CAT. NO.
Glutaraldehyde sol. 25%, extra pure	GL0170
Glutaraldehyde sol. 50%, extra pure	GL0168

DEHYDRATION MEDIA

Wet fixed tissues cannot be directly infiltrated in paraffin. First, the water from tissues must be removed by dehydration. This is usually done with a series of alcohols, for example 70% to 96% to 100%.

DESCRIPTION	CAT. NO.
Ethanol 70%, synthesis grade	ET0001
Ethanol 96%, extra pure	ET0003
Ethanol absolute, extra-pure	ET0002

CLEARING AGENTS

Clearing agents remove the dehydrant and must be miscible with both, the dehydrant and the embedding medium. Xylene is the most broadly used solvent in histology. Also toluene or trichloroethane are sometimes used as clearing and dewaxing agents when preparing samples for further inspection by microscopy. As all these solvents are toxic and environment unfriendly, it is advisable to avoid their use.
Scharlau offers you an alternative, non toxic, virtually odour free solvent for histology: Histodisol.
Histodisol is a new mineral oil product that replaces aromatic solvents in histology. Since it has the same solvent properties as xylene, it can be used as a clearing and dewaxing agent without changing protocols. It is totally miscible with ethanol, 2-propanol, acetone and butanol and has a specially good paraffin absorption capacity. With Histodisol you won’t need to change the rinsing baths so often in order to take paraffin away.
Histodisol can be used in automated instruments. Its short evaporation period enables faster and more effective work. It doesn’t leave resin residue which is very important when working with automatic robots.
Histodisol is also an economic alternative to xylene.

DESCRIPTION	CAT. NO.
Histodisol, solvent for histology	HI0500

For those hystologists who prefer using xylene or toluene, we now offer a new quality LOW IN BENZENE, according to the directive CEE L398/19. This directive demands a concentration of max. 0,1% of benzene.

DESCRIPTION	CAT.NO.
Xylene, mixture of isomers, hystology grade, low in benzene	XI0052
Toluene, hystology grade, low in benzene	TO0086

EMBEDDING MEDIA

Once the tissue has been fixed, it must be processed into a form which can be made into thin microscopic sections. This is usually done with paraffin.

We provide different types of paraffins in pellets to be used as embedding media for histology or microscopy. Our plastic paraffin is a blend of paraffin wax and plastic polymers. It has been found that, when plastic polymers are added to the paraffin, the elasticity of the final block is greater as compared to paraffin alone. The mixture also offers improved tissue penetration.

DESCRIPTION	CAT. NO.
Paraffin plastisized m.p. 56-58°C, pellets	PA0113
Paraffin plastisized m.p. 52-54°C, pellets	PA0114
Paraffin m.p. 56-58°C, pellets	PA0112

MOUNTING MEDIA

DPX MOUNTING MEDIUM

This colourless, synthetic resin is a rapid mounting medium for microscopy. Minimizing drying time is critical to successful slide presentation. A fast drying mounting medium prevents moisture from developing under the coverglass and, the consequent clouding of the specimen. Our DPX mounting medium is fast-drying. 5 minutes after its application, coverglass remains fixed. Because of its fast drying period it is not recommended for use with thick sections.

DESCRIPTION	CAT. NO.
DPX Mounting Medium	DP0050

STAINS IN SOLUTION

In most cases, staining with appropriate dyes is necessary to make cells and their organelles visible under microscope. We do offer stains for haematology, bacteriology and cytology.

HAEMATOLOGY

May Grünwald Giemsa staining
In this procedure two stains are combined: May Grünwald and Giemsa. They act selectively when released into a buffered aqueous solution. May Grünwald stains acidophilic cells and the neutrophilic granulations of leukocytes. Giemsa stains monocyte and lymphocyte cytoplasm and nuclear chromatin.

DESCRIPTION	CAT.NO.
Eosin methylene blue, solution according to May Grünwald	EO0056
Azur-eosin-methylene blue solution (in methanol), according to Giemsa, modified	AZ0391
Buffer solution pH 7	SO1007

BACTERIOLOGY

Gram staining
Gram negative bacteria may be distinguished from Gram positive bacteria through the nature of their bacterial walls and permeability to alcohol. In the staining procedure, dye-iodine complexes are formed with the bacterial wall. In Gram positive bacteria this complexes cannot be dissolved from the bacterial cells with decolouring agents and the cells remain dark violet. Gram negative bacterial cells are decoloured and then counterstained with safranine or carbol fuchsin in orange or pink.

Gram-Hücker and Gram-Nicolle protocols are used. In Gram Hücker procedure, Phenylic gentian violet is replaced by crystal violet oxalate and carbolated fuchsin by safranine.

Gram Hücker

DESCRIPTION	CAT. NO.
Bleaching agent, solution according to Gram	DE0010
Crystal violet oxalate, solution      according to Gram Hücker	VI0027
Lugol’s solution, for microscopy	LU0010
Safranine, solution according to Gram	SA0042

Gram Nicolle

DESCRIPTION	CAT. NO.
Bleaching agent solution according to Gram	DE0010
Fuchsin basic, carbol solution,      according to Ziehl Neelsen	FU0065
Gentian violet, carbol solution, for microscopy	VI0032
Lugol’s solution, for microscopy	LU0010

Mycobacteria staining
Certain mycobacteria, for example, tuberculosis bacteria, doesn’t release stain on acid treatment, once it has been absorbed. This fact is the principle of Ziehl Neelsen staining. Ziehl Neelsen carbol fuchsin is used to stain all bacteria: after an acid treatment, only mycobacteria rest stained in pink. Finally, carbol methylene blue is added to counterstain preparation.

DESCRIPTION	CAT. NO.
Carbol fuchsin, solution according to Ziehl Neelsen	FU0065
Bleaching agent, acid solution according to Gram	DE0011
Methylene blue, carbol solution, for microscopy	AZ0206

To avoid phenolic vapours produced when heating carbol fuchsin during the Ziehl Neelsen staining, several alternative cold staining methods have been developed. We offer two kits for fast cold staining of mycobacteria:

DESCRIPTION	CAT. NO.
Tb-Quick staining kit	TB0015
Tb-Quick Fluo staining kit	TB0016

We are printing a detailed brochure about these kits. Please, ask to your distributor.

CYTOLOGY

Papanicolaou’s staining

Papanicolaou’s smear test is used worldwide to screen cervix cancer in women. Staining procedure involves Haematoxylin, that should give excellent nuclear definition, and the cytoplasmic stains, OG 6 and EA 50, that should produce the correct coloration, subtle contrasts and delicate coloration, to allow cytologists to identify different types of cells.

DESCRIPTION	CAT. NO.
Haematoxylin according to Harris, solution for cytology	HE0060
Papanicolaou’s solution EA 50	SO1050
Papanicolaou’s solution OG 6	SO1051

In this catalogue, you will also find our traditional range of stains in solid form.