Clarifier™ 1 is a reagent designed to eliminate background staining sometimes caused by excessive adhesives in the water bath such as gelatin. Clarifier™ 1 selectively removes hematoxylin staining from excess adhesive without affecting nuclear staining. This product is only effective with progressive staining and should not be used with regressive stains. Clarifier™ 1 is designed for use after staining with progressive hematoxylins. After tissues have been sufficiently stained with a progressive hematoxylin, slides are removed from the stain and excess hematoxylin is removed by rinsing the sections in water. The sections are then placed into Clarifier™ 1 for 30 seconds to 1 minute. A 1-minute water rinse should follow as this stops the reaction and rinses excess acid from the tissue section. If Clarifier™ 1 is not successful in removing the background staining, use Clarifier™ 2 in its place with a possible time reduction.

Clarifier™ 2 is an aqueous glacial acetic acid rinse designed to eliminate background staining sometimes caused by excessive adhesives in the water bath such as gelatin. Clarifier™ 2 selectively removes hematoxylin staining from excess adhesive without affecting nuclear staining. This product is only effective with progressive staining an should not be used with regressive stains. Clarifier 2 was designed to be used in histology only. Clarifier™ 2 is designed for use after staining with progressive hematoxylins. After tissues have been sufficiently stained with a progressive hematoxylin, slides are removed from the stain and excess hematoxylin is removed by rinsing the sections in water. The sections are then placed into Clarifier™ 2 for 20 seconds to 40 seconds. A 1-minute water rinse should follow as this stops the reaction and rinses excess acid from the tissue section.

Cyto-Stain™ G is a modification of Cyto-Stain™, designed to produce greener cyanophilic hues in intermediate and basal cells, and is used in the same manner as Cyto-Stain™.

Cyto-Stain™ acts as a single-solution cytoplasmic stain, producing the full range of familiar colors seen in conventional Papanicolaou staining and providing complete control of staining intensity. The staining of Cyto-Stain™ is accomplished through a formulation based upon the differential affinities of its component dyes for various cellular components. Final cytoplasmic hues are influenced by both the prior action of Clarifier 1 and the subsequent 95% alcohol rinses. Cyto-Stain™ produces results comparable to Pap staining with one minor difference: cilia in bronchial washings stain blue-green with Cyto-Stain™ rather than red as seen in traditional Pap staining procedures

Cyto-Stain™ acts as a single-solution cytoplasmic stain, producing the full range of familiar colors seen in conventional Papanicolaou staining and providing complete control of staining intensity. The staining of Cyto-Stain™ is accomplished through a formulation based upon the differential affinities of its component dyes for various cellular components. Final cytoplasmic hues are influenced by both the prior action of Clarifier 1 and the subsequent 95% alcohol rinses. Cyto-Stain™ produces results comparable to Pap staining with one minor difference: cilia in bronchial washings stain blue-green with Cyto-Stain™ rather than red as seen in traditional Pap staining procedures

OG-6 and Modified OG are ready-to-use cytoplasmic counterstains that stain keratinized cells orange. A well-preserved or fixed slide with adequate exposure to 95% alcohol or a commercial spray fixative is highly recommended for optimal staining results.OG-6 has a specific affinity for keratinized cells and will not stain other cellular constituents. When used in conjunction with EA stains, the end user can expect traditional staining results that are consistent and familiar. Stain filtering is recommended to remove cells shed off of slides in the cytology staining process.

OG-6 is a traditional formulation that, when used with various EA products, will provide familiar staining results for gynecological and non-gynecological specimens.

OG-6 is a traditional formulation that, when used with various EA products, will provide familiar staining results for gynecological and non-gynecological specimens.

Modified OG is used in conjunction with EA products for staining gynecological and non-gynecological specimens. This formulation is optimized to reduce precipitate formation and staining times common with traditional OG-6 formulations. Modified OG and Modified EA, when used together, will reduce filtering and staining times.

EA-36, -50, -65 and Modified EA are ready-to-use cytoplasmic counterstains used for gynecological and non-gynecological cytology specimens. These products contain common dyes and reagent solvents used in traditional EA formulations. A well-preserved or fixed slide with adequate exposure to 95% alcohol or a commercial spray fixative is highly recommended for optimal staining results. Cellular results are traditional as well, with basal or intermediate cells staining a blue-green hue and surface cells staining a pink-red hue. This multicolored effect is due to dye uptake by various cells and their affinities for the specific dyes.EA-36 is used in conjunction with OG-6 for the staining of gynecological specimens. It will provide a slightly lighter cytoplasmic hue than EA-50. EA-36 is recommended for end users who desire a more pastel staining result in gynecological specimens.

EA-36, -50, -65 and Modified EA are ready-to-use cytoplasmic counterstains used for gynecological and non-gynecological cytology specimens. These products contain common dyes and reagent solvents used in traditional EA formulations. A well-preserved or fixed slide with adequate exposure to 95% alcohol or a commercial spray fixative is highly recommended for optimal staining results. Cellular results are traditional as well, with basal or intermediate cells staining a blue-green hue and surface cells staining a pink-red hue. This multicolored effect is due to dye uptake by various cells and their affinities for the specific dyes.EA-36 is used in conjunction with OG-6 for the staining of gynecological specimens. It will provide a slightly lighter cytoplasmic hue than EA-50. EA-36 is recommended for end users who desire a more pastel staining result in gynecological specimens.

EA-36, -50, -65 and Modified EA are ready-to-use cytoplasmic counterstains used for gynecological and non-gynecological cytology specimens. These products contain common dyes and reagent solvents used in traditional EA formulations. A well-preserved or fixed slide with adequate exposure to 95% alcohol or a commercial spray fixative is highly recommended for optimal staining results. Cellular results are traditional as well, with basal or intermediate cells staining a blue-green hue and surface cells staining a pink-red hue. This multicolored effect is due to dye uptake by various cells and their affinities for the specific dyes.EA 50 is used in conjunction with OG-6 for the staining of gynecological specimens. It will provide a very traditional staining result with common staining hues and intensities. EA-50 can also be used for non-gynecological specimens however, although EA-65 is recommended.

EA-36, -50, -65 and Modified EA are ready-to-use cytoplasmic counterstains used for gynecological and non-gynecological cytology specimens. These products contain common dyes and reagent solvents used in traditional EA formulations. A well-preserved or fixed slide with adequate exposure to 95% alcohol or a commercial spray fixative is highly recommended for optimal staining results. Cellular results are traditional as well, with basal or intermediate cells staining a blue-green hue and surface cells staining a pink-red hue. This multicolored effect is due to dye uptake by various cells and their affinities for the specific dyes.EA 50 is used in conjunction with OG-6 for the staining of gynecological specimens. It will provide a very traditional staining result with common staining hues and intensities. EA-50 can also be used for non-gynecological specimens however, although EA-65 is recommended.

EA-36, -50, -65 and Modified EA are ready-to-use cytoplasmic counterstains used for gynecological and non-gynecological cytology specimens. These products contain common dyes and reagent solvents used in traditional EA formulations. A well-preserved or fixed slide with adequate exposure to 95% alcohol or a commercial spray fixative is highly recommended for optimal staining results. Cellular results are traditional as well, with basal or intermediate cells staining a blue-green hue and surface cells staining a pink-red hue. This multicolored effect is due to dye uptake by various cells and their affinities for the specific dyes.EA 50 is used in conjunction with OG-6 for the staining of gynecological specimens. It will provide a very traditional staining result with common staining hues and intensities. EA-50 can also be used for non-gynecological specimens however, although EA-65 is recommended.

EA-36, -50, -65 and Modified EA are ready-to-use cytoplasmic counterstains used for gynecological and non-gynecological cytology specimens. These products contain common dyes and reagent solvents used in traditional EA formulations. A well-preserved or fixed slide with adequate exposure to 95% alcohol or a commercial spray fixative is highly recommended for optimal staining results. Cellular results are traditional as well, with basal or intermediate cells staining a blue-green hue and surface cells staining a pink-red hue. This multicolored effect is due to dye uptake by various cells and their affinities for the specific dyes.EA-65 is used in conjunction with OG-6 for the staining of non-gynecological specimens. This formulation contains less dye resulting in lighter staining of highly mucoid sample types common in non-gynecological cytology.

EA-36, -50, -65 and Modified EA are ready-to-use cytoplasmic counterstains used for gynecological and non-gynecological cytology specimens. These products contain common dyes and reagent solvents used in traditional EA formulations. A well-preserved or fixed slide with adequate exposure to 95% alcohol or a commercial spray fixative is highly recommended for optimal staining results. Cellular results are traditional as well, with basal or intermediate cells staining a blue-green hue and surface cells staining a pink-red hue. This multicolored effect is due to dye uptake by various cells and their affinities for the specific dyes.EA-65 is used in conjunction with OG-6 for the staining of non-gynecological specimens. This formulation contains less dye resulting in lighter staining of highly mucoid sample types common in non-gynecological cytology.

EA-36, -50, -65 and Modified EA are ready-to-use cytoplasmic counterstains used for gynecological and non-gynecological cytology specimens. These products contain common dyes and reagent solvents used in traditional EA formulations. A well-preserved or fixed slide with adequate exposure to 95% alcohol or a commercial spray fixative is highly recommended for optimal staining results. Cellular results are traditional as well, with basal or intermediate cells staining a blue-green hue and surface cells staining a pink-red hue. This multicolored effect is due to dye uptake by various cells and their affinities for the specific dyes.EA-65 is used in conjunction with OG-6 for the staining of non-gynecological specimens. This formulation contains less dye resulting in lighter staining of highly mucoid sample types common in non-gynecological cytology.

Modified EA is used in conjunction with OG-6 or Modified OG for gynecological and non-gynecological specimens. This formulation does not contain Bismarck Brown and is optimized to reduce precipitate formation that is common with other traditional EA formulations. The Modified EA staining results are most similar to EA-50.

The Amyloid Stain kit is a special stain technique to identify amyloid in tissue sections. Amyloid, a fiber-like protein, can be stained with Congo Red solution. Sodium Hydroxide is added to the solution to break down hydrogen bonds between adjacent amyloid fibers allowing more bonding sites for the Congo Red. A light counterstain with Mayer’s hematoxylin allows contrast. Amyloid can be best detected by the use of green birefringence under a polarized lens of a light microscope. Care should be taken to section tissue sections at a thickness of 7-10 microns for optimal staining.

Iron Stain Kit is an in vitro diagnostic medical device intended to be used by laboratory professionals for the qualitative evaluation of ferric iron in pathology specimens. Iron Stain Kit is intended for use as an aid in identifying iron in tissue sections for the diagnosis of general pathology specimens.

Periodic Acid-Schiff Stain Kit is a staining kit used to detect carbohydrates, glycogen, basement membranes, and fungus in tissue sections for the diagnosis of general pathology specimens. Periodic acid oxidizes these various tissue moieties to aldehydes, to which Schiff Reagent bonds in its colorless form. Rinsing with water removes the sulfurous acid and restores the Schiff Reagent to its rose-colored form.

Fungal cell walls are rich in polysaccharides known as glucans. Periodic Acid Solution oxidizes these polysaccharides to form aldehydes, which in turn react with the silver ions present in the Working Methenamine Silver Solution and reduce them to form visible metallic silver. Gold Chloride Solution tones the sections and intensifies the reduced silver by forming a silver-gold complex. Sodium Thiosulfate Solution removes any unreduced silver from the tissue sections, followed by Fast Green Stain Solution which produces a light green background to further enhance contrast.

Modified Steiner-Steiner Silver Stain Kit aids in identifying spirochetes and non-filamentous bacteria in tissue sections for the diagnosis of general pathology specimens. Microorganisms that stain positively with this technique have a cell wall that will adsorb silver from a silver solution (argyrophilic). The silver is first adsorbed in a non-visible form and is subsequently reduced by the Working Reducing Solution (hydroquinone) to a visible metallic silver.

Methyl Green-Pyronin-Y Stain Solution is intended for used in differentiating DNA and RNA in tissue sections for the diagnosis of general pathology specimens. The reaction is based upon the competition between the slow staining, but doubly charged, methyl green and the more rapidly staining, singly charged pyronin Y. Methyl green has two cationic charged groups that become linked to the phosphate moieties in the DNA. The pyronin Y displaces the methyl green from all sites of linkage except where its double charge gives it a selective advantage (acidic polymer such as DNA). Consequently, the methyl green stains DNA and retains its binding to this substance against the competitive action of pyronin Y. Pyronin Y stains the less polymerized RNA rapidly and displaces methyl green from linkages having smaller polymeric acidic substances (RNA). The reaction is done at pH 4.2 – pH 4.3. The advantage of a low pH is to have the nucleic acids in a charged condition and in their least soluble state.

Mucicarmine demonstrates an affinity for mucins of epithelial origin. Aluminium is thought to form a chelation complex with carmine that binds with negatively charged acid mucins

Gram Stain Kits – Tissue & Film Bacteria can be classified into one of two families based upon structural and compositional differences in their cell walls. Gram-positive bacteria have thick cell walls with high peptidoglycan content, whereas Gram-negative bacteria have thin cell walls with low peptidoglycan content. Both Gram-positive and Gram-negative bacteria stain with the dye- lake formed by Crystal Violet Solution and Gram’s Iodine Solution. However, during rinsing with Decolorizing Solution, this dye-lake is completely removed from the thin-walled Gram- negative bacteria, allowing them to be subsequently stained with Safranin O Stain Solution. The short duration of the decolorization step enables Gram-positive bacteria to retain the crystal violet dye-lake. Care should be taken when rinsing slides with Decolorizing Solution, as extended rinses can cause the crystal violet dye-lake to be removed from Gram-positive bacteria in addition to Gram-negative bacteria. Within the Tissue Kit only, tissue elements are then counterstained yellow by Tartrazine Stain Solution.

The Acid Fast Bacillus Stain Kit (87016) and components are for use as a kit in special stain techniques to detect acid fast bacteria. A waxy, lipid-rich cell wall surrounds the acid fast bacterium. This cell wall absorbs carbol fuchsin but is resistant to decoloration with acid alcohol. Bacteria that do not have a lipid-rich cell wall easily decolorize leaving the acid fast bacillus. Loeffler Methylene Blue Stain Solution provides a light blue counterstain to provide contrast for surrounding tissue elements from the brick red acid fast bacillus.

Elastic Stain Kit and its components are used as a special stain kit to identify elastic fibers. The elastic fibers stain black due to the dye lake created by the hematoxylin, ferric chloride and iodine mixture. The fibers are overstained and then differentiated with ferric chloride to break the dye-lake complex. To ensure fibers are not over-differentiated, slides should be examined during this step under the microscope. Elastic fibers will be stained black and sharply defined. The Van Gieson solution then counterstains the tissue with collagen staining red and other tissue structures, yellow. The Van Gieson solution will also remove some of the elastic fiber staining so the knowledge of a professional is required for adequate use. After staining, care should be taken in choosing a compatible mounting medium as some mountants can leach the picric acid from the Van Gieson counterstain.

The Acid Fast Bacillus Stain Kit (87016) and components are for use as a kit in special stain techniques to detect acid fast bacteria. A waxy, lipid-rich cell wall surrounds the acid fast bacterium. This cell wall absorbs carbol fuchsin but is resistant to decoloration with acid alcohol. Bacteria that do not have a lipid-rich cell wall easily decolorize leaving the acid fast bacillus. Loeffler Methylene Blue Stain Solution provides a light blue counterstain to provide contrast for surrounding tissue elements from the brick red acid fast bacillus.

The Acid Fast Bacillus Stain Kit (87016) and components are for use as a kit in special stain techniques to detect acid fast bacteria. A waxy, lipid-rich cell wall surrounds the acid fast bacterium. This cell wall absorbs carbol fuchsin but is resistant to decoloration with acid alcohol. Bacteria that do not have a lipid-rich cell wall easily decolorize leaving the acid fast bacillus. Loeffler Methylene Blue Stain Solution provides a light blue counterstain to provide contrast for surrounding tissue elements from the brick red acid fast bacillus.

The Amyloid Stain kit is a special stain technique to identify amyloid in tissue sections. Amyloid, a fiber-like protein, can be stained with Congo Red solution. Sodium Hydroxide is added to the solution to break down hydrogen bonds between adjacent amyloid fibers allowing more bonding sites for the Congo Red. A light counterstain with Mayer’s hematoxylin allows contrast. Amyloid can be best detected by the use of green birefringence under a polarized lens of a light microscope. Care should be taken to section tissue sections at a thickness of 7-10 microns for optimal staining.

The Amyloid Stain kit is a special stain technique to identify amyloid in tissue sections. Amyloid, a fiber-like protein, can be stained with Congo Red solution. Sodium Hydroxide is added to the solution to break down hydrogen bonds between adjacent amyloid fibers allowing more bonding sites for the Congo Red. A light counterstain with Mayer’s hematoxylin allows contrast. Amyloid can be best detected by the use of green birefringence under a polarized lens of a light microscope. Care should be taken to section tissue sections at a thickness of 7-10 microns for optimal staining.

The Amyloid Stain kit is a special stain technique to identify amyloid in tissue sections. Amyloid, a fiber-like protein, can be stained with Congo Red solution. Sodium Hydroxide is added to the solution to break down hydrogen bonds between adjacent amyloid fibers allowing more bonding sites for the Congo Red. A light counterstain with Mayer’s hematoxylin allows contrast. Amyloid can be best detected by the use of green birefringence under a polarized lens of a light microscope. Care should be taken to section tissue sections at a thickness of 7-10 microns for optimal staining.

Elastic Stain Kit and its components are used as a special stain kit to identify elastic fibers. The elastic fibers stain black due to the dye lake created by the hematoxylin, ferric chloride and iodine mixture. The fibers are overstained and then differentiated with ferric chloride to break the dye-lake complex. To ensure fibers are not over-differentiated, slides should be examined during this step under the microscope. Elastic fibers will be stained black and sharply defined. The Van Gieson solution then counterstains the tissue with collagen staining red and other tissue structures, yellow. The Van Gieson solution will also remove some of the elastic fiber staining so the knowledge of a professional is required for adequate use. After staining, care should be taken in choosing a compatible mounting medium as some mountants can leach the picric acid from the Van Gieson counterstain.

Elastic Stain Kit and its components are used as a special stain kit to identify elastic fibers. The elastic fibers stain black due to the dye lake created by the hematoxylin, ferric chloride and iodine mixture. The fibers are overstained and then differentiated with ferric chloride to break the dye-lake complex. To ensure fibers are not over-differentiated, slides should be examined during this step under the microscope. Elastic fibers will be stained black and sharply defined. The Van Gieson solution then counterstains the tissue with collagen staining red and other tissue structures, yellow. The Van Gieson solution will also remove some of the elastic fiber staining so the knowledge of a professional is required for adequate use. After staining, care should be taken in choosing a compatible mounting medium as some mountants can leach the picric acid from the Van Gieson counterstain.

Elastic Stain Kit and its components are used as a special stain kit to identify elastic fibers. The elastic fibers stain black due to the dye lake created by the hematoxylin, ferric chloride and iodine mixture. The fibers are overstained and then differentiated with ferric chloride to break the dye-lake complex. To ensure fibers are not over-differentiated, slides should be examined during this step under the microscope. Elastic fibers will be stained black and sharply defined. The Van Gieson solution then counterstains the tissue with collagen staining red and other tissue structures, yellow. The Van Gieson solution will also remove some of the elastic fiber staining so the knowledge of a professional is required for adequate use. After staining, care should be taken in choosing a compatible mounting medium as some mountants can leach the picric acid from the Van Gieson counterstain.

Gram Stain Kits – Tissue & Film Bacteria can be classified into one of two families based upon structural and compositional differences in their cell walls. Gram-positive bacteria have thick cell walls with high peptidoglycan content, whereas Gram-negative bacteria have thin cell walls with low peptidoglycan content. Both Gram-positive and Gram-negative bacteria stain with the dye- lake formed by Crystal Violet Solution and Gram’s Iodine Solution. However, during rinsing with Decolorizing Solution, this dye-lake is completely removed from the thin-walled Gram- negative bacteria, allowing them to be subsequently stained with Safranin O Stain Solution. The short duration of the decolorization step enables Gram-positive bacteria to retain the crystal violet dye-lake. Care should be taken when rinsing slides with Decolorizing Solution, as extended rinses can cause the crystal violet dye-lake to be removed from Gram-positive bacteria in addition to Gram-negative bacteria. Within the Tissue Kit only, tissue elements are then counterstained yellow by Tartrazine Stain Solution.

Alcian Blue reacts to compounds containing anionic groups such as acid mucosubstances and acid mucins. At pH 2.5, both carboxylated and sulfated acid mucosubstances are stained blue. Periodic acid is used to oxidize the tissue to form aldehyde groups that are demonstrated by Schiff Reagent. Glycogen and neutral mucosubstances as well as basement membranes will be stained magenta by Schiff Reagent, followed by a tap water rinse to develop and intensify its magenta hues. An optional counterstain may be used to provide nuclear detail. Hematoxylin 7211 is recommended; however, Kernechtrot Nuclear Fast Red may be used if a red nuclear stain is desired

Alcian Blue reacts to compounds containing anionic groups such as acid mucosubstances and acid mucins. At pH 2.5, both carboxylated and sulfated acid mucosubstances are stained blue. Periodic acid is used to oxidize the tissue to form aldehyde groups that are demonstrated by Schiff Reagent. Glycogen and neutral mucosubstances as well as basement membranes will be stained magenta by Schiff Reagent, followed by a tap water rinse to develop and intensify its magenta hues. An optional counterstain may be used to provide nuclear detail. Hematoxylin 7211 is recommended; however, Kernechtrot Nuclear Fast Red may be used if a red nuclear stain is desired

Periodic Acid-Schiff Stain Kit is a staining kit used to detect carbohydrates, glycogen, basement membranes, and fungus in tissue sections for the diagnosis of general pathology specimens. Periodic acid oxidizes these various tissue moieties to aldehydes, to which Schiff Reagent bonds in its colorless form. Rinsing with water removes the sulfurous acid and restores the Schiff Reagent to its rose-colored form.

Biebrich Scarlet-Acid Fuchsin is utilized to stain the acid substances such as the cytoplasm, muscle and collagen. Phosphotungstic-Phosphomolybdic (PTA-PMA) solution is then used to remove the Biebrich Scarlet from the collagen fibers. The cytoplasm will retain the stain due to its permeability. The Aniline Blue is then utilized to restain the decolorized collagen fibers. A 1% Acetic Acid solution may further be used to differentiate the stained tissue section

Modified Steiner-Steiner Silver Stain Kit aids in identifying spirochetes and non-filamentous bacteria in tissue sections for the diagnosis of general pathology specimens. Microorganisms that stain positively with this technique have a cell wall that will adsorb silver from a silver solution (argyrophilic). The silver is first adsorbed in a non-visible form and is subsequently reduced by the Working Reducing Solution (hydroquinone) to a visible metallic silver.

Modified Grocott’s Methenamine Silver Stain Kit (Chromic Acid) is intended for use as an aid to identify fungal organisms and basement membranes in tissue sections for the diagnosis of general pathology specimens. Fungal cell walls are rich in polysaccharides known as glucans. Treatment with either periodic acid or chromic acid oxidizes these polysaccharides to form aldehyde groups; however, chromic acid is the stronger oxidizer. Chromic acid will achieve a greater degree of oxidation, rendering some chemical groups non-reactive with silver so that they are not demonstrated within the final stain. This greater level of oxidation also results in reduced background staining of basement membranes and collagen fibers, as well as more effective demonstration of Pneumocystis jiroveci (formerly classified as Pneumocystis carinii) and Histoplasma capsulatum (the causative organism of Histoplasmosis). After oxidation, Sodium Metabisulfite Solution removes residual Chromic Acid Solution from the tissue. The aldehyde groups react with the silver ions present in the Working Methenamine Silver Solution and reduce them to form visible metallic silver. Gold Chloride Solution tones the sections and intensifies the reduced silver by forming a silver-gold complex. Sodium Thiosulfate Solution removes any unreduced silver from the tissue sections, followed by Fast Green Stain Solution which produces a light green background to further enhance contrast.

Modified Grocott’s Methenamine Silver Stain Kit (Chromic Acid) is intended for use as an aid to identify fungal organisms and basement membranes in tissue sections for the diagnosis of general pathology specimens. Fungal cell walls are rich in polysaccharides known as glucans. Treatment with either periodic acid or chromic acid oxidizes these polysaccharides to form aldehyde groups; however, chromic acid is the stronger oxidizer. Chromic acid will achieve a greater degree of oxidation, rendering some chemical groups non-reactive with silver so that they are not demonstrated within the final stain. This greater level of oxidation also results in reduced background staining of basement membranes and collagen fibers, as well as more effective demonstration of Pneumocystis jiroveci (formerly classified as Pneumocystis carinii) and Histoplasma capsulatum (the causative organism of Histoplasmosis). After oxidation, Sodium Metabisulfite Solution removes residual Chromic Acid Solution from the tissue. The aldehyde groups react with the silver ions present in the Working Methenamine Silver Solution and reduce them to form visible metallic silver. Gold Chloride Solution tones the sections and intensifies the reduced silver by forming a silver-gold complex. Sodium Thiosulfate Solution removes any unreduced silver from the tissue sections, followed by Fast Green Stain Solution which produces a light green background to further enhance contrast.

Modified Grocott’s Methenamine Silver Stain Kit (Chromic Acid) is intended for use as an aid to identify fungal organisms and basement membranes in tissue sections for the diagnosis of general pathology specimens. Fungal cell walls are rich in polysaccharides known as glucans. Treatment with either periodic acid or chromic acid oxidizes these polysaccharides to form aldehyde groups; however, chromic acid is the stronger oxidizer. Chromic acid will achieve a greater degree of oxidation, rendering some chemical groups non-reactive with silver so that they are not demonstrated within the final stain. This greater level of oxidation also results in reduced background staining of basement membranes and collagen fibers, as well as more effective demonstration of Pneumocystis jiroveci (formerly classified as Pneumocystis carinii) and Histoplasma capsulatum (the causative organism of Histoplasmosis). After oxidation, Sodium Metabisulfite Solution removes residual Chromic Acid Solution from the tissue. The aldehyde groups react with the silver ions present in the Working Methenamine Silver Solution and reduce them to form visible metallic silver. Gold Chloride Solution tones the sections and intensifies the reduced silver by forming a silver-gold complex. Sodium Thiosulfate Solution removes any unreduced silver from the tissue sections, followed by Fast Green Stain Solution which produces a light green background to further enhance contrast.