Thermo Fisher Scientific Introduces Family of Protein Molecular Weight Markers

Thermo Fisher Scientific introduces a family of protein molecular weight standards for use in monitoring protein separation during SDS polyacrylamide gel electrophoresis. These standards enable researchers to determine approximate molecular weight of proteins and verify Western blot transfer efficiency. All markers are made with Fermentas technology, which was acquired by the Thermo Fisher Scientific in the summer of 2010.

The Thermo Scientific Pierce Protein Molecular Weight Ladders, the most economical option within the product family, are available pre-stained or unstained. The Pierce® Pre-stained Protein Molecular Weight Ladders contain seven single-color proteins, varying in size from 14.4 to 116 kilodaltons. The Pierce Unstained Protein Molecular Weight Ladders contain six proteins from 20 to 120 kilodaltons and can be used with coomassie-based and silver stains.

The Thermo Scientific PageRuler Unstained Protein Ladders offer the user a choice of three molecular weight ranges for more accurate determinations and can be detected with coomassie or silver stains. The standard PageRuler™ Unstained Protein Ladders provide a mixture of 14 proteins, ranging from 10 to 200 kilodaltons. The PageRuler Broad Range Unstained Protein Ladder contains 11 proteins from 5 to 250 kilodaltons. Lastly, the PageRuler Low Range Unstained Ladder provides a mixture of seven proteins from 5 to 100 kilodaltons. All PageRuler Unstained Ladders contain at least one protein band of greater intensity for reference. The proteins in all ladders also carry the Strep-Tag II sequence for direct detection on Western blots using a Strep-tag detection system.

The tri-color PageRuler and PageRuler Plus Pre-stained Proteins Ladders offer a further level of convenience. The PageRuler Pre-stained Ladder contains 10 proteins, ranging from 10 to 170 kilodaltons, and two different colored bands for reference. The PageRuler Plus Pre-stained Ladder consists of nine proteins from 10 to 250 kilodaltons, with two orange reference bands and one green band. All other proteins in both ladders carry a blue chromophore.

Lastly, the pre-stained Thermo Scientific Spectra Multicolor Protein Ladders are available in three different size ranges for more precise analysis. The Spectra™ High Range Protein Ladder contains proteins from 40 to 300 kilodaltons, making it ideal for analysis of large proteins, whereas the Spectra Low Range contains proteins from 1.7 to 40 kilodaltons for small protein research. A broad range Spectra Protein Ladder is also available for more general applications.

All Thermo Scientific Pierce Protein Molecular Weight Ladders come in a variety of package sizes. As a convenience, all ladders are supplied in gel loading buffer and are ready to use without heating or boiling.