Tannic Acid to Z6040
Tannic Acid, Reagent, A.C.S., EM Grade

C76H52O46   F.W. 1701.28   CAS #1401-55-4

Tannic Acid, Reagent, A.C.S.

Gallotannin; Chiefly   (C14H10O9)n   F.W. range 1000.00-1500.00  CAS #1401-55-4
Low Molecular Weight. Suitable for electron microscopy

Takagi, M., Parmley, R.T., Denys, F.R. and Kageyama, M. (1983). Ultrastructural visualization of complex carbohydrates in epiphyseal cartilage with the tannic acid-metal salt methods. J. Histochem. Cytochem.,31:783
Simionescu, N. el al., J. Cell Biol., 70:608 (1976) A Combination of Tannic acid Glutaraldehyde Osmium Tetroxide (TAGO) Method. improving membranes contrast.
Roubos, E. W. and Van DerWal-Divendel, R.M. (1980). Ultrastructural analysis of peptide-hormone released by exocytosis. Cell Tiss. Res., 207:267
Buma, P.,Roubos, E.W. and Buijs, R.M. (1984). Ultrastructural demonstration of exocytosis of neural, neuroendocrine, and endocrine secretions with an in vitro tannic acid (TARI) method. Histochemistry, 80:247
Buma, P. and Nieuwenhuys, R. (1987). Ultrastructural demonstration of oxytocin and vascopressin release sites in the neural lobe and median eminence of the rat by tannic acid and immunogold methods. Neurosci. Lett., 74:151
Brooks, J.C. and Carmicheal, S.W. (1987). Ultrastructural demonstration of exocytosis in intact and saponin-permeabilized cultured bovine chromaffin cells. Am. J. Anat., 178:85
Technovit: Glycol Methacrylate Embedding Kits

C16H20N2   F.W.240.35   CAS #54827-17-7
m.p. 166-169°C
Assay >98%
A non-carcinogenic substitute for DAB and DAB-HCl. Used as a sensitive and specific reagent for the detection of blood.

Standefer, J.C., Vanderjagt, D. (1977) Assay of Hemoglobin. Clin. Chem. 23, 749.
Boss, E.S., et al., (1981). Assay of Peroxidases. J. of Immunoassay. 2,187.
Holland, V.R., et al., (1974) Tetrahedron, 30, 3299.
TMB-HCl, Dihydrochloride TMB

C16H20N2·2HCl   F.W. 313.30   CAS #64285-73-0
m.p. >300°C
Assay >98% (Cl)

Also available in tablet form. 1mg/ tablet, ready to use.

(TMA), Tetramethylene Glycol

(1,4-Butanediol dimethacrylate)
[H2C=C9CH3)CO2CH2CH2] 2   F.W. 226.68
CAS #2082-81-7
Specific Gravity (H2O=1) : 1.023
b.p. @4 mmHg 132-134°C
Inhibited with 200 ppm hydroquinone monomethyl ether.

TMS, Tetramethylsilane, 99.9%

Si(CH3)4   M.W. 88.22
b.p. 26.6-26.7°C
Flashpoint: 28°C

An organo-silicon compound tetramethylsilane (TMS) is used as an internal standard for nuclear magnetic resonance (NMR). It is chemically inert and has a boiling point of 26.6°C which is lower than acetone (53.6°C), and other highly volatile liquids, such as diethyl ether (34.5°C) and 1,2-epoxy propane (36.4°C). It is soluble in most organic solvents but insoluble in water. All of these properties make TMS an ideal solvent for tissue drying, which preserves excellent tissue surface details. Dey, Sudip. Et al. (1989). A new rapid method of air-drying for scanning electron microscopy using tetramethylsilane. J. of Microscopy, Vol 156, pp. 259-261.

(TC-NBT), Thiocarbamyl Nitro-Blue Tetrazolium

(2,2′-Di[p-nitrophenyl]-5,5′-di[p-thiocarbamylphenyl] -3,3′-[3,3′-dimethoxy-4,4′-biphenylene]ditetrazolium chloride)
C42H32Cl2N12O6S2   F.W. 935.8   CAS #36889-43-7

Nitro-Blue Tetrazolium
(TCH), Thiocarbohydrazide, Highest Purity

H2NNHCSNHNH2   F.W. 106.15   CAS #2231-57-4
b.p. 171°C (decomposed)
Osmiophilic reagent.

An indefinite shelf life due to a special purification process.
Seligman A.M. et al (1965).Histochemical demonstration of some oxidized macromolecules with thiocarbohydrazide (TCH) or thiosemicarbazide (TSC) and osmium tetroxide. J. Histochem. Cytochem., 13:629
Seligman, A.M. et al (1966). A new staining method (OTO) for enhancing contrast of lipid-containing membranes and droplets in osmium tetroxide fixed tissue with osmiophilic thiocarbohydrazide (TCH). J. Cell Biol., 30:424
Thiery, J.P. (1967). Mise en evidence des polysaccharides sur coupes fines en microscopie electronique. J. Microsc., 6:987
Lo, H.K. et al (1987). A modified periodic acid-thiocarbo-hydrazide-silver proteinate staining sequence for enhanced contrast and resolution of glycogen depositions by transmission electron microscopy. J. Histochem. Cytochem., 35:393
Neiss, W.F. (1988). Enhancement of the periodic acid-Schiff (PAS) and periodic acid-thiocarbohydrazide-silver proteinate (PA-TCH-SP) reaction in LR White sections. Histochemistry, 88:603
Hanker, J.S. et al (1964). Osmiophilic reagents: new cytochemical principles for light and electron microscopy. Science, N.Y., 146:1039
Derenzini, M., et al (1986). An improved periodic acid-thiosemicarbazide-osmium technique to reveal glyco-conjugates at the molecular level in situ. J. Histochem. Cytochem.,34:1161
Thiosemicarbazide, Reagent, A.C.S.

NH2CSNHNH2   F.W. 91.14   CAS #79-19-6
m.p. 181-183°C
Assay >99.0%
References for use-see Thiocarbohydrazide

Tissue Marking Dyes


Toluene Reagent, A.C.S.

C6H5CH3   FW 92.14   CAS #108-88-3
Specific Gravity (H2O=1): 0.866
b.p. 110-111°C (230-222°F)
Assay. 99.9%

Color (A.P.H.A.) 10
Residue after evaporation 0.001%
Subs. darkened by H2SO4 To pass test
Sulfur compound (as S) 0.003%
Water 0.03%
Toluidine Blue 0, Certified, C.N. #DcU-10

(Basic blue; Methylene Blue T50 or T Extra)
C15H16N3SCl   FW 305.83   CAS #92-31-9
Dye Content: approx. 85% min.
Solubility: 3.25% Water; 1.75% Alcohol; 3.5% Cellosolve; 5.5% Glycol; 0.0% Xylene
*-A general stain for epoxy thick sections. Barajas et al.(1981) Identification of renal neuroeffector junctions by electron microscopy of reembedded light microscopic autoradiograms of semithin sections. J. Ultrastruct. Res. 77: 379.Campbell, R.D., And Hermans, C.O. (1972). A rapid method for resectioning 0.5 4.0 micron epoxy sections for electron microscopy. Stain Technol. 47:115.

Technical Tip


Tricresyl Phosphate

(Tritolyl Phosphate)
(CH3C6H4O)3PO   F.W. 368.37   CAS #1330-78-5
Specific Gravity (H2O=1): 1.16
A mixture of isomeric Tritolyl Phosphates, usually excluding the very toxic group ortho-isomer. Used to prepare benzoyl peroxide paste, which acts as a catalyst for water miscible resins.





Tris (Hydroxymethyl) Aminomethane,Free-base, Reagent Grade

White crystalline powder
C4H11NO3   F.W. 121.14   CAS #77-86-1
A 40% (w/v) aqueous solution. It is clear and colorless.
Assay >99.9%
Water .<0.2%
Heavy Metals.-2ppm

Tris Buffer pH 10.0 (10x)

Description: This buffer is intended for heat-induced antigen retriever on formalin-fixed paraffin-embedded (FFPE) tissue sections prior to application of antibodies. In IHC most commonly used fixative like formalin mask tissue antigens (cellular, membrane and nuclear) by cross-linking process, this results in poor or no staining in IHC. The use of this buffer on FFPE tissue section improves accessibility of antibodies to tissue antigens.
Storage: 2-8°C. DO NOT FREEZE
Intended Use: 1x buffer solution is intended for heat-induced antigen retriever in IHC. Please refer to primary antibody protocol.
Reagent: 10x, pH 10 antigen retriever solution.
Preparation of Working Solution: Dilute this 10x buffer as needed (e.g. 90 ml of deionized or distilled water + 10 ml of this buffer), mix well, 1x buffer can be stored at 2-8°C.

Triton® X-100

(Polyethylene glycol tert-octylphenyl ether)
CAS #9002-93-1
Specific Gravity (H2O=1): 1.065

Triton® X-100, 1% Aqueous Solution

Prepared 1% Triton X-100 in Deionized-Distilled water. Used for whole-cell preparations. Marek, L.F., and Kelly, R.O. (1983). A simple technique for the visualization of whole mount cytoskeletons with transmission electron microscopy. Anat. Rec. 207, 365. Pudney, J., and Singer, R.H. (1980). Intracellular filament bundles in whole mounts of chick and human myoblasts extracted with Triton X-100. Tissue cell 12, 595.

Triton® X-100, 0.08% Aqueous Solution

A prepared solution for the cleaning of diamond knives.

Trypsin Reagent

Description: Trypsin is used for proteolytic digestion of formalin-fixed paraffin-embedded (FFPE) tissue sections prior to application of antibodies. In IHC most commonly used fixative like formalin; mask tissue antigens (cellular, membrane and nuclear) by cross-linking process, this results in poor or no staining in IHC. Trypsin digestion improves immunoreactivity of some antigens in FFPE tissue sections. For cytokeratin clone AE3 and AE1/AE3, this enzyme works much better than boiling the tissue with citrate buffer.
Storage: 2-8°C. DO NOT FREEZE
Intended Use: Use as antigen retriever for some antibodies in IHC. Please refer to primary antibody protocol for IHC.
Reagent: This enzyme is supplied as concentrated form along with buffer. The kit comes in 2 sizes:
Small: Reagent B (Buffer) is 15 ml and the Reagent E (Enzyme) is 2 ml
Large: Reagent B (Buffer) is 100 ml and the Reagent E (Enzyme) is 10 ml

12-Tungstosilicic Acid

(Silicotungstic acid)
H4[SiO4.(W3O9)4]·xH2O   M.W. 2878.29+aq   CAS #11130-20-4

Tyrode Solution

Ingredients: NaCl; KCl; CaCl2.6H2O; MgCl2.6H2O; NaHCO3; NaH2PO4; Glucose; and Distilled water.

Ordering Information:
Uranyl Acetate, Reagent, A.C.S.

UO2(OCOCH3)2·2H2O   F.W. 424.14
CAS #541-09-3
Assay 98.0-102.0%

Insoluble Matters 0.01
Chloride 0.003%
Sulfate 0.01%
Alkalies (as SO4) 0.05%
Heavy Metals 0.002%
Iron 0.001%

A universal EM stain for thin sections, en-block staining, and negative staining.



“I am so happy. I read on your web site that UranyLESS hadn’t been tested for negative staining and I wanted you to know that I think it did a spectacular job on this sample!” – Debra Townley, Baylor College of Medicine

Substitute for Uranyl Acetate

EMS is proud to introduce UranyLess, a new contrast stain solution for TEM, for all of your negative staining applications. It is an amazing substitute for Uranyl Acetate with similar results.

After only a minute of contact, UranyLess’ fast-acting, non-radioactive lanthanide mix is finished staining your sections or deposits (see protocols below). If needed, lead citrate is recommended to increase the contrast. TIP: To prevent precipitates, use room temperature distilled water.

UranyLess’s pH level is about 6.8-7. The 30ml airless bottle will stain approximately 1500 grids. The airless bottle increases shelf life, eliminates CO2 contamination, and produces less waste – the solution pumps out in perfect amounts without leaking or spilling. UranyLess is also available in a larger amount for use in automated staining equipment. When using UranyLess for automated staining, do not wash longer than 10 minutes or you run the risk of losing all contrast.

UranyLess has been tested on many biological tissue (animal and plant): intestine, skeletal and cardiac muscle, liver, kidney, adrenal gland, nerve, cell culture, plant tissue, and also on negative staining of bacteriophage, bacteria, and polymers. UranyLess is ideal because of its ability to stain any kind of material and results are reproducible. To see the effectiveness of Uranyless, please visit the UranyLess Image Gallery.https://www.youtube.com/embed/GHeUlhDq4m8

Lead Citrate 3%

Lead Citrate 3%

UranyLess has a strong contrasting power, however, we recommend a Lead Citrate counterstain to enhance the contrast. You can follow the protocol of the UranyLess / Lead Citrate double contrast by watching the video. EMS recommends Lead Citrate 3%, ready to use. The special pump delivers the product without letting in air, thus preserving the solution and preventing CO2 dissolution. It is convenient to use because it performs in any position, even upside down. Comes in either a 30 ml Airless bottle or a 30ml Airless Syringe. The Syringe is meant to be used exclusively with the RMC TEM Stainer QG3100


“Easier and Safer Biological Staining: High Contrast UranyLess Staining of TEM Grids using mPrep/g Capsules.” Benmeradi N1,2, Payre B2 and Goodman SL3.

Delta Microscopies, 22 bis, route de Saint Ybars, 31190 Mauressac, France
Université Toulouse, CMEAB Faculté Medecine, 118 route Narbonne, 31062, Toulouse, France
Microscopy Innovations LLC, 213 Air Park Rd, Suite 101, Marshfield, WI, 54449, USA

“C-Nap1 mutation affects centriole cohesion and is associated with a Seckel-like syndrome in cattle.” Nature Communications. Published 23 Apr 2015. Sandrine Floriot, all.

* in airless bottle
** Syringe is meant to be used exclusively with the RMC TEM Stainer QG3100

UAR-EMS Uranyl Acetate Replacement Stain

A non-radioactive substitute for uranyl acetate with comparable results. Avoids the tedious authorization, shipping and disposal issues involving uranyl acetate without sacrificing performance. Two lanthanide salts, samarium and gadolinium triacetate, effectively used for staining plastic-embedded animal and plant tissues. Also for negative staining of macromolecules. Not recommended as a fixative.

Platinum Blue, an EM Stain

IBI Blue Platinum Stain Pt4N8H6O24C20

An EM stain that may have the ability to replace Uranyl Acetate in some instances. If you have issues with having Uranium salts that are radioactive (depleted or not) in the lab this may be the answer for you. An alternative for staining TEM thin sections

Uranyl Acetate Solution

We are now offering Uranyl Acetate pre-made and ready to use solution for making your work easier. The following percentages are avaialble off the shelf (1, 2, 3, 4). Other percentages are avaialble upon request.

Uranyl Formate


F.W. 378.08
CAS #16984-59-1
For ultra fine grain structure, our Uranyl Formate offers amazing advancement in negative staining for microscopy.

Purity 99.9-100%
Specific Gravity 3.695
Appearance Yellow Crystals
Melting Point 110°C
Ordering Information:
Uranyl Magnesium Acetate



CAS # 20596-93-4

Used as a substitute for uranyl acetate in either double-staining techniques and also as a solo stain.

Uranyl Nitrate, Hexahydrate

Reagent Grade, A.C.S.

F.W. 502.13

CAS #13520-83-7

Purity 99.9-100%
Density 2.807 g/cm3
Solubility ~66g/100g H2O
Melting Point 60°C
Boiling Point 118°C
Insoluble Matter <0.005%
Chloride (Cl) <0.002%
Sulfate (SO4) <0.005%
Alkalies % Alkaline Earths (Sulfates) <0.1%
Heavy Metals (as Pb) <0.002%
Iron (Fe) <0.002%
Substances Reducing Permanganate (as UIV) <0.06%

A Universal EM Negative Stain used for viruses. In tissue samples it stabilizes nucleic acids and cell membranes. These solutions are more stable than uranyl acetate and they react primarily with negatively charged groups in the absence of phosphate ions.

Uranyl Oxalate

(COO)2 UO2 ·.3H2O


To adjust the pH of Uranyl compounds as well as a negative stain for electron microscopy.

Uranyl Zinc Acetate


CAS # 10138-94-0

F.W. 571.59

Used as a laboratory reagent in the determination of sodium concentrations of solutions.

Technical Tips:


Van Gieson’s Solution

To use with Weigert’s Iodine or Weigert’s Iron as a connective tissue stain.

Water Deionized, Reagent Grade A.C.S.

H2O F.W. 18.02 CAS #7732-18-5
EMS Reagent Grade Water is typically prepared at 18 megohm/cm specific resistance using a reverse osmosis, mixed deionization, activated filtration and final filtration at 0.2 microns.
Color (APHA) <+/-5
Bacteriological purity 0 CFUs/L
Residue after evaporation 10ppm
Coliform negative

Weigert’s Iodine Solution

A histological stain. Demonstration of connective tissue is useful in cases of emphysema, arteriosclerosis and other vascular diseases

Weigert’s Iron Hematoxylin

Stain selectivity for nuclei, fungal, and general applications. Ready-to-use.

Wright Stain, Certified #DcWr-38

CAS #68988-92-1
Solubility: 0.091% Water; 0.23% Alcohol

Wright Staining Solution

For use as a blood stain. Ready-to-use.

Xylenes, Reagent, A.C.S.

(Xylol, Dimethylbenzene)
C6H4(CH3)2   FW 106.27   CAS #1330-20-7
Specific Gravity (H2O=1): 0.865
b.p. 136-140°C
This reagent is a mixture of isomers (ortho, meta, and para) and may contain Ethylbenzene.

Color (A.P.H.A.) 10
Subs. darkened by H2SO4 To pass test
Sulfur Compounds (as S) 0.003%
Water 0.05%
Residue after evaporation 0.002%
Xylene: Peanut oil, 2:1
Xylene Substitute

A xylene substitute for use in histology and cytology. It is safer and a more preferable alternative to xylene. It can be used as a solvent and clearing agent, as well as for dissolving paraffin waxes, glues and adhesives.

Minimal tissue shrinkage
Dries slowly with no residue
Less toxic than xylene
Soluble with alcohol, paraffin embedding media, and mounting media

It can be used in all procedures that require xylene. Biodegradable.

SlideBrite™ Xylene Substitute

The safest choice for a xylene alternative available today

Reduce your risks & enhance your personnel safety with “The Original” high quality performance clearing agent. It performs equal-to or better than Xylene, yet smells like water! A non-hazardous clearing agent, it is non-flammable and odorless, with no vapor disguising additives.

Enhances nuclear detail
Fast slide drying time
Gentle, yet very effective deparaffinization
No tissue shrinkage or morphology change
No brittle tissue subsequent to tissue processing


Histosol™ Xylene Substitute

Histosol™ is the original high flash point (114°F TCC) histological clearing agent. It is intended to be used as a replacement for xylene where the hazards associated with aromatic hydrocarbon vapors are to be reduced. Museum-quality tissue slides can be prepared with Hitosol without change in protocol or procedure. Histosol is manufactured from petrochemical products and is miscible in all proportions with ethanol, isopropanol, and t-butanol. It is also miscible with all paraffin-based tissue embedding media and all permanent mounting materials.

Hemo-De®* Xylene Substitute

An intensive study from 1992 throughout 2000 has shown that Hemo-De® (d-Limonene) a terpene-based chemical with a pleasant citrus fragrance, was able to replace many of the clinical laboratories toxic reagents, such as carbol-xylene, xylene, ethyl acetate and formalin.

In Parasitology – Hemo-De replaces ethyl acetate in the concentration procedure; Hemo-De replaces carbol-xylene, xylene and formalin in the trichrome procedure.

In Histology – Hemo-De replaces xylene in most all procedures. Hem-De is a superior solvent and Clearing agent that can be used in all tissue processing, deparaffiniating and slide preparation.

Hemo-De Features
Soluble with alcohol and mounting media
Biodegradable, non-corrosive, non-flammable (Combustible)
Contains no benzene and no toluene
Low toxicity levels
Minimal tissue shrinkage
Reasonably fast drying and leaves no residue
Hemo-De Application

In Research and Medical – Hematology, Cytology, Pathology, Microbiology, Histology, Pathology, Hospital

In Mechanical Applications – Cleaning of machine parts, cleaning tools, engines etc.

In Electronic Applications – Circuits boards, electronic components, tools.

General Applications – Clean metal and glass surfaces. Dilute with water can be used to clean all plastic surfaces. Removal of adhesives, glues, tars…

Hemo-De Information
Chemical name: d-Limonene (Terpene Hydrocarbon, n.o.s.)
Composition: d-Limonene, CAS [5989-27-5]98.0%
Butylated Hydroxyanisolve (BHA), CAS
Flash Point (TCC): 121°F (49.4°C)
Boiling Point: 349°F (176°C) @ 760mmHg
Freezing Point: -74°C
Shipping: Terpene Hydrocarbons, n.o.s. ID No.
04858003, Flammable Liquid, Group III
W.E. Aldeen and D. Hale. “Use of Hem-De to eliminate toxic agents used for concentration and trichrome staining of intestinal parasites” J. of Clinical Microbiology, July 1992, 1893- 1895, Vol. 30, No. 7
Metzger, Zvi DMD et al. “Gutta-Percha Softening: ‘Hem-De’ as a Xylene Substitute” J. of Endodontics”. 26(7):385-388, July 2000.
Devon C. Hale, MD; et al. “Use of a Single Slide Trichrome- Stained Concentrate for the detection of intestinal Parasites Stained Concentration Procedure for Ova and Parasites” American Journal of Clinical Pathology, Vol. 106, N0. 2. Aug. 1996.
J. M. Miller et al. “Biodegradable, effective substitute for xylene in the Ehrlich indole procedure”. J. of Clinical Microbiology, Aug. 1994, 2028-2030, Vol 32, No 8.

*Hemo-De® is a product of Scientific Solvents.

Histo-Clear®/Histo-Clear II®

Histo-Clear® (Distilled essential oils – food grade) and Histo-Clear II® (A mixture of Aliphatic Hydrocarbon and Distilled essential oils – food grade, reduced citrus odor) are excellent non-toxic clearing agents replacing Xylene.

Z-Fix Concentrate

Z-Fix Concentrate

Concentrate for buffered aqueous zinc formalin

Zinc formalin fixatives improve general morphology and immunohistochemical staining and can reduce or eliminate the need for antigen recovery procedures while preserving immunoreactivity for months.

Compatible with all tissue processors
May be used in place of neutral buffered formalin
Easy to dilute with water
Make 5 gallons of fixative using just one gallon of concentrate
Z6040 Embedding Primer

This unique primer affords you a better adhesion between your resin and specimen that you are embedding and prevents the sample from pulling away from the resin during sectioning.