Paraformaldehyde to Picric
Paraformaldehyde, EM Grade,
Purified
(Polyoxymethylene)
OH(CH2O)n H F.W. Average: 600 CAS #30525-89-4
Paraformaldehyde is the condensation product of methylene glycol, a substance
not so far isolated in its pure form; it is a white solid with a formaldehyde
content between 78 and 98% and is supplied either as a Prill or Granular.
All forms contain more than 95.5% paraformaldehyde content. The Prill and
Granular forms are small, free-flowing, dust-free beads, the most desired
by EM users. A fast-penetrating EM fixative used in combination with Glutaraldehyde,
Acrolein, and Osmium Tetroxide. Karnovsky, M.J., J. Cell Biol., 27, 137A
(1965). Hayat, M.A. Principles & Tech., of EM (Univ. Park Press), 68
(1981)
| RT | 19200 | Prill | 500g | 13.00 | Add to Cart | |
| RT | 19202 | Prill | kilo | 20.00 | Add to Cart | |
| RT | 19208 | Granular | 500g | 12.00 | Add to Cart | |
| RT | 19210 | Granular | kilo | 19.00 | Add to Cart |
Technical Tip

Paraformaldehyde Aqueous Solution -16%
(Formaldehyde Aqueous Solution, 16%)
CAS #30525-89-4
Prepared from Paraformaldehyde crystal, 16% aqueous solution, methanol free.
Microfiltered and stored in pre-scored ampoules.
| RT | 15700 | 16% Paraformaldehyde (formaldehyde) aqueous solution | 10 ml | 5.00 | Add to Cart |
| RT | 15710 | 16% Paraformaldehyde (formaldehyde) aqueous solution | 10x10 ml | 23.50 | Add to Cart |
| RT | 15711 | 16%Paraformaldehyde (formaldehyde) aqueous solution, same as 15710 | 10bxs/lot | 220.00 | Add to Cart |
We can prepare in accordance to your special requirements (any concentration desired). Call for more information.
See Formaldehyde Solution, for other standard concentrations.

Paraformaldehyde-Glutaraldehyde
Solution Karnovsky's Fixative
Ready To mix. Kit consists of: 2x10 ml ampoules 16% Formaldehyde1x10 ml
ampoules 50% Glutaraldehyde1x50 ml 0.2M Sodium Phosphate Buffer
| 0-5°C | 15720 | 1 kit | 18.00 | Add to Cart | |
| 0-5°C | 15730 | Lot of 5 kits | 80.00 | Add to Cart |
Paramat and Paramat Extra
Please see listing in Embedding Media for Histology and Light Microscopy.
Tissue-TEK Paraffin
Please see listing in Embedding Media.
Paraplast Embedding Medium


Paraplast X-tra
Handy pellet form melts rapidly. Melting Point 53-54°C. Cuts to 2 micron thickness with exceptional ribbon continuity. Extra compression resistance provides total support of tissues
| RT | 19214 | Paraplast X-tra | 1 kilo | 15.75 | Add to Cart |
| RT | 19215 | Paraplast X-tra | 8 kilo | 98.00 | Add to Cart |

Paraplast Plus
Reduces infiltration time by one-third. Cuts to 2 micron thickness with excellent ribbon continuity. Convenient pellet form melts rapidly. Melting point 56°C. Double filtered. No need for filtration before use.
| RT | 19216 | Paraplast Plus | 1 kilo | 15.00 | Add to Cart |
| RT | 19217 | Paraplast Plus | 8 kilo | 96.50 | Add to Cart |

Paraplast Medium
Handy pellet form melts rapidly. Melting Point 56°C
Cuts to 4 micron thickness with excellent ribbon continuity - no Crumbling
or cracking.
Double filtered. No need for filtration before use.
| RT | 19218 | Paraplast Medium | 1 kilo | 16.00 | Add to Cart |
| RT | 19219 | Paraplast Medium | 8 kilo | 99.00 | Add to Cart |
Paraffin Waxes
For a continuation of our Paraffin Waxes, please see listing in Embedding Media.
Articles of Interest
Re-Embedding of Paraffin Embedded Specimens in Resin
Paraffin - Peel-A-Way® Embedding
Wax
For our complete line of Embedding Waxes, please see Embedding Media for Histology and Light Microscopy
PEG
- GMA/PEG Embedding Kit,
Please see listing in Embedding Media Kits.

Parlodion (Pyroxylin Purified
Strips)
C12H16N4O18 F.W.
504.28 CAS #9004-70-0
Highly purified from cellulose nitrate; specially prepared for embedding
tissue for sectioning and for preparing semi-permeable membranes.
| RT | 19220 | 10g | 74.00 | Add to Cart |
Parlodion 2% in Amyl Acetate
See Collodion, 2% .

Periodic Acid, Reagent
H5IO6 F.W. 227.96 CAS #10450-60-9
| Assay | >99.0% | |
| Heavy Metals | .0.005% | |
| Insoluble Matters | 0.01% | |
| Iron | .0.003% | |
| Other Halogen (Cl) | 0.01% | |
| Residue after Ignition | 0.01% | |
| Sulfate | 0.01% |
Used as a Fixative: Issidorides, M.R., and Kasorchis, T. (1981).
Dispersed and compact chromatin demonstrated with a new EM Method: phosphotungstic
acid-hematoxylin block-staining. Histochemistry 73,21
Used widely as a Negative Stain:
- As Spray method: Horne, R.W., and Pasquali-Ronchette, I. (1974). A negative staining-carbon film technique for studying viruses in the electron microscope.
- Preparation procedures for examining icosahedral and filamentous viruses. J. Ultrastruct. Res. 47, 361. Locke, M., and Kirhman, N. (1971).
- Hot Alcoholic phosphotungstic acid and uranyl acetate as routine stains for thick and thin sections. J. Cell Biol., 50, 550., Farragiana, T., and Marinozzi, V. (1979).
- Phosphotungstic acid staining of polysaccharides containing structures on epoxy embedded tissues. J. Submicrosc. Cytol. 11, 263.Bloom, E.E., And Aghajanian, G.K. (1968).
- Fine structural and cytochemical analysis of the staining of synaptic junctions with PTA. J. Ultrastruct. Res. 22, 261
| RT | 19325 | 25 g | 32.00 | Add to Cart |
Periodic Acid Solutions
Please see listing in Reagents for Histology
Permount™ Mounting
Medium
Please see listing in Adhesives and Mountants

Phenol Red
(Phenolsulfonphthalein)
C19H14O5S F.W. 354.38 CAS
#143-74-8
A standard indicator for preparing buffers, pH range 6.4-8.2.
| RT | 19327 | 5 g | 17.00 | Add to Cart |
Phenol Red Sodium Salt
(Phenolsulfonphthalein Sodium Salt)
C19H13NaO5S F.W. 376.37 CAS
#34487-61-1
A standard indicator for preparing buffers, pH range 6.8-8.2.
| Assay | >99.0% | |
| Water | <0.1% |
| RT | 19328 | 5 g | 26.00 | Add to Cart |

(PMSF), Phenylmethylsulphonyl
Fluoride
C6H5CH2SO2F F.W. 174.20 CAS #329-98-6
| Assay | >99.0% | |
| Water | <0.1% |
| RT | 19330 | 1g | 19.00 | Add to Cart | |
| RT | 19331 | 5g | 90.00 | Add to Cart |
Phosphate Mixed Sodium Salts 0.2 M Buffer
Please see listing in Prepared Buffers.
| RT | 11600-05 | 500 ml | 18.00 | Add to Cart | |
| RT | 11600-10 | 1 L | 27.00 | Add to Cart |

Phloxine B, Certified, C.I.
#45410
(Acid Red 92; Cyanosine; Eosin 10B; Phloxine TA, N, BP
Super, RB, TB, or BB)
C20H2O5Cl4Br4Na2 F.W.
829.66 CAS #18472-87-2
Solubility: 10.5% Water; 5.0% Alcohol; 9.0% Cellosolve; 4.5% Glycol; 0.0% Xylene
| RT | 19350 | 25 g | 36.00 | Add to Cart |

Phosphomolybdic Acid, Crystal,
Reagent, A.C.S.
(dodeca-Molybdophosphoric Acid)
H3PO4·12(MoO3)·24H2O F.W.
2257.6 CAS #51429-74-4
| RT | 19400 | 100g | 85.00 | Add to Cart |
Phosphomolbdic Acid Solutions
Please see listing in Reagents for Histology

Phosphotungstic Acid, Crystal,
Reagent, Highest Purity
(Tungstophosphoric Acid)
H3[P(W3O10)4] aq F.W. 2880.17+aq CAS
#12501-23-4
Specifications:
| Solubility | Practically clear, colorless solution. |
|
| Ammonia (NH ) | 0.004% | |
| Chloride (Cl) | 0.03% | |
| Insoluble Matter | 0.02% | |
| Nitrate (NO3 ) | 0.004% | |
| Sulfate (SO4 ) | 0.005% | |
| Heavy Metals and Iron. | No color formation on addition of Hydrogen Sulfide |
Used as a Fixative:
Issidorides, M.R., and Kasorchis, T. (1981).
Dispersed and compact chromatin demonstrated with a new
EM Method: phosphotungstic acid-hematoxylin block-staining.
Histochemistry 73,21
Used widely as a Negative Stain:
- As Spray method: Horne, R.W., and Pasquali-Ronchette, I. (1974). A negative staining-carbon film technique for studying viruses in the electron microscope.
- Preparation procedures for examining icosahedral and filamentous viruses. J. Ultrastruct. Res. 47, 361. Locke, M., and Kirhman, N. (1971).
- Hot Alcoholic phosphotungstic acid and uranyl acetate as routine stains for thick and thin sections. J. Cell Biol., 50, 550.,Farragiana, T., and Marinozzi, V. (1979).
- Phosphotungstic acid staining of polysaccharides containing structures on epoxy embedded tissues. J. Submicrosc. Cytol. 11, 263.Bloom, E.E., And Aghajanian, G.K. (1968).
- Fine structural and cytochemical analysis of the staining of synaptic junctions with PTA. J. Ultrastruct. Res. 22, 261
| RT | 19500 | 100g | 54.00 | Add to Cart |
Phosphotungstic Acid Solutions
Please see listing in Reagents for Histology
Picric Acid, Reagent, Crystal,
A.C.S.
(2,4,6-Trinitrophenol)
C6H2(NO2) 3OH FW 229.11 CAS
#88-89-1
A.C.S. Specifications:
| Water | min 30% | |
| Melting Point (dried) | 121-123°C | |
| Insoluble in Resinous Matter. | 0.01% | |
| Insoluble in benzene | 0.1% | |
| Sulfate | 0.01% |
| RT | 19550 | 100g | 72.00 | Add to Cart |
Picric Acid Solutions
Please see listing in Reagents for Histology







