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P3143 Sigma-Aldrich

Poly(ethyleneimine) solution

analytical standard, 50 % (w/v) in H2O

Synonym: Ethyleneimine polymer solution, PEI



Related Categories Cell Lysis and Protein Extraction Reagents, Molecular Biology, Native Protein Sample Preparation, Protein Sample Clarification, Proteomics More...
grade   analytical standard
mol wt   Mn ~60,000
  Mw 750,000
concentration   50 % (w/v) in H2O
application(s)   gel permeation chromatography (GPC): suitable
format   single component solution


Frequently Asked Questions

Frequently Asked Questions are available for this Product.


PEI cellulose in small columns will separate cyclic nucleotides from related compounds at the same electrolyte concentration that is used for thin layer chromatography on PEI cellulose-coated plates.

Biochem/physiol Actions

Water soluble polymer used as a membrane lubricant; useful in filtering frozen cell membranes.


1 L in poly bottle

100, 500 mL in poly bottle


PEI cellulose should be washed extensively in distilled water, then washed three times with 10-20 volumes of 5 mM acetic acid, removing fines during each wash. After final settling, one volume of cellulose is suspended in three volumes of 5 mM acetic acid.

Price and Availability

Ultrafree Centrifugal Filter Units
Safety & Documentation

Safety Information

Signal word 
Hazard statements 
Precautionary statements 
UN 3082 9 / PGIII
WGK Germany 

Frequently Asked Questions

Which document(s) contains shelf-life or expiration date information for a given product?
If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis. These documents are located on the product detail page under Useful Links & Tools. Click on the following link to search for a Certificate of Analysis. Please click the following link to see the details on our Product Dating Information.
How do I get lot-specific information or a Certificate of Analysis?
A Certificate of Analysis is available by lot number and can be obtained through our Advanced Search Option: http://www.sigmaaldrich.com/catalog/AdvancedSearchPage.do
What is the molar concentration of Product P3143, Poly(ethyleneimine) solution?
This product is nominally a 50% w/v solution of PEI in water, meaning 50 grams of poly(ethyleneimine) per 100 mL of solution. Concentrations of polymer solutions (such as PEI) are commonly reported either as a percentage or mg/mL, not in terms of molarity.
The product description of Product P3143, Poly(ethyleneimine) solution, on sigmaaldrich.com appears to give two molecular weight values, Mn and Mw. What do those abbreviations stand for, and why are the two values so different?
Mn is the number average molecular weight.  This corresponds to the “true average” or mean; that is, the sum of the molecular weights divided by the number of molecules. Mw is the weight average molecular weight. This corresponds to the median value; that is, there are as many molecules smaller than the weight average molecular weight as there are larger than the weight average molecular weight. The fact that the two molecular weight values are so different means that there is a large, non-symmetrical distribution of molecular weights; the largest molecules probably have a molecular weight of several million.
What is the purity of Product P3143, Poly(ethyleneimine) solution?
This product is a polymer with a large molecular weight distribution. It is not amenable to being analyzed by typical chromatographic assays such as HPLC or TLC. Therefore, we do not report an overall purity value for this product.
Do you have any references that describe using Product P3143, Poly(ethyleneimine) solution, in enzyme isolation or for transfections?
For enzyme isolation, see: J.J. Jendrisak and R.R. Burgess, Biochem., 14(21), 4639-4645 (1975), "A new method for the large-scale purification of wheat germ DNA-dependent RNA polymerase II". This paper describes preparing a 10% stock solution, which was adjusted to pH 7.9 by adding hydrochloric acid. PEI has also been used for the precipitation of nucleic acids in the purification process of aminoacyl-tRNA synthetases: von der Haar, F., “Purification of Aminoacyl-tRNA Synthetases”, Methods in Enzymology, 59, 257-267 (1979). For transfections, see the following references: Boussif, O. et al., "A versatile vector for gene and oligonucleotide transfer into cells in culture and in vivo: Polyethylenimine." Proc. Natl. Acad. Sci. USA, 92(16), 7297-7301 (1995). Thomas, M. and Klibanov, A.M., Conjugation to gold nanoparticles enhances polyethylenimine's transfer of plasmid DNA into mammalian cells. Proc. Natl. Acad. Sci. USA, 100(16), 9138-9143 (2003).
How do I find price and availability?
There are several ways to find pricing and availability for our products.  Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers. 
What is the Department of Transportation shipping information for this product?
Transportation information can be found in Section 14 of the product's (M)SDS. To access the shipping information for this material, use the link on the product detail page for the product, or search here. 
My question is not addressed here, how can I contact Technical Service for assistance?
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