SPI-Chem™ Parlodion^® Resin Strips, Purified

Direct replacement in most experiments calling for collodion, "Celloidin", "Pyroxylin™","LVN" and sometimes, "cellulose nitrate"

Explanation of Hazardous Labels

Appearance: Thin transparent colorless to pale yellow strips
Formula: C₁₂H₁₆N₄O₁₈
Odor: None reported
Solubility in water: Insoluble
CAS #9004-70-0
RTECS #QW0970000
Specific Gravity: 1.66 @ 20°C/4°C
Melting Point: 165°C (329°F); ignites
Ash (w/w): 0.50% maximum
UN 1325 Hazard Class: 4.1 Flammable Solid, Packing Group II

This is the preferred Cellulose nitrate for TEM support films and the making of replicas.

Parlodion is manufactured by nitrating (with nitric acid) and then sulfating (with sulfuric acid) relatively ordinary cotton to make it (as a result of the addition of soluble nitrate and sulfate groups) soluble. When dried, the solids become what is known as "gun cotton" because of its original use as gun powder.

We believe that these other materials are very similar but to Parlodion^® does have a unique and specific corporate and process origin and is unlikely to be exactly identical to these other material alternatives. At the very least, one could expect that the degree of nitrating and sulfating might vary from manufacturer to manufacturer, thereby resulting in some variation in the final properties such as molecular weight, purity, etc. whereas one could not have such confidence with generic collodion of unknown origin. This could of course help explain why one researcher might have difficulty repeating someone else's work. Most researchers report obtaining similar results, whether the application is for the casting of a film for TEM grids or for the making of replicas on metallurgical or ceramic types of surfaces. On the other hand, not everyone seems to experience equivalent results, which then again, might not be that surprising. To repeat one more time, we believe Parlodion to be similar but not necessarily identical to the products called "Celloidin" and also, "LVN", or "low viscosity nitrocellulose".

All of the above mentioned products are supposed to be less explosive than the original "gun cotton".

These materials, e.g. all of the above mentioned products based on cellulose nitrate, at one time, were also used widely as embedding resins, but have been replaced in most applications by more modern materials. However, for the embedding of really large samples, a technique called "double embedding" still requires a Parlodion or nitrocellulose type material. However, for specific kinds of samples, there might be a preference for one or the other of the nitrocellulose based materials.

Some other applications include its use as an aid in the retention of paraffin sections on a slide. However it is not useful with any enzymes as it acts as an effective filter to prevent their penetration. It is also permanently stained by dyes such as celestine blue B.

Parlodion, as well as all of the sister nitrocellulose based materials are flammable solids and require great care in their handling. However, the generally high cost of their transport can be mitigated by purchasing the quantities specified by the

symbol since in those cases, the shipping costs are fairly similar to that of shipping a material that was not hazardous.

In view of the above, we would like to add one further clarification: Whereas Parlodion is the registered trade name of specific company, and if one purchases a bottle marked as being Parlodion, then that material should be traceable back to that original manufacturer, and one should have the confidence that one batch after the other is going to be exactly the same, lot after lot, batch after batch. It is therefore our recommendation that one should purchase for EM applications only product clearly identified as Parlodion and for that reason.

To the best that we can determine, the term "collodion" is a generic description of this type of material. What is in a bottle or vial marked "collodion" could have come from anywhere. There is no real assurance that a vial so marked for one lot number would necessarily be the same identical material for some other lot number. One place for variation in the properties of the final product is in the % nitration that has occurred. SPI Supplies purchased from a former major supplier of EM consumables a quantity of product labeled as "collodion". We did not know the origin of this generically labeled material except for anyone wanting to repeat experiments calling for collodion that particular material came from what was once called the Polaron consumables (and later Bio-Rad Microscience EM consumables) product line. And for a while, we could assure such purchasers that this was the source of the collodion then being offered by SPI Supplies. However, we have exhausted our supply of this particular source of collodion, and now we offer in its place only Parlodion, the brand of collodion manufactured by the Monsanto Chemical Company.

One last comment about this:
When referring to "collodion", being that it is a generic word and is not the recognized trade name of anyone, there is no need to capitalize or make any other reference. However, when referring to "Parlodion", it should always be shown as Parlodion ^® for a first time use on a particular page.

Parlodion solutions:
The dissolution of Parlodion takes time, and many customers prefer to order their Parlodion already dissolved in amyl acetate. It is for that reason that we recommend one consider purchasing amyl acetate that can be used as a diluent for protocols using less than a 2% solution.

A safety tip:
It has been reported that one should use only amyl acetate as the solvent for Parlodion or its sister compounds. Ethyl ether/alcohol solutions are thought to be dangerous because if ether peroxidation has occurred, the sample could explode upon drying. One hundred years ago, photographers trying to make photographic emulsions with collodion materials in their "base" were killed in just those kinds of explosions. Just remember that the making of high quality TEM grid support films is truly an "art" and does take most people some amount of time to learn. Therefore, once you have decided to do your own grid coating, then take advantage of some of the tips from the SPI grid coating experts! Or if you would rather short circuit the time otherwise needed to look at your important samples, consider the purchase of grids already custom coated by SPI Supplies.

		SPI #	Each	In Stock
	10g	02465-BA	$ 54.90	Yes
	25g	02465-CF	120.78	No
	100g	02465-MB	434.80	Yes
2% Parlodion™ in Amyl Acetate Filtered and ready to use
		SPI #	Each	In Stock
	30 ml	02458-DA	$ 17.57	Yes
	100 ml	02458-MB	50.62	Yes

Storage Conditions: Room temperature
Material is hazardous from the stand point of shipping

Amyl acetate diluent:
		SPI #	Each	In Stock
	30 ml	02461-AA	$ 5.49	Yes
	500 ml	02461-AB	27.45	Yes

Storage Conditions: Room temperature
Material is hazardous from the stand point of shipping

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Contacting SPI Supplies and Structure Probe, Inc.
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SPI-Chem™ Parlodion® Resin Strips, Purified

SPI-Chem™ Parlodion^® Resin Strips, Purified