Protein Standards & Ladders - IT (2024)

FAQs

What is a protein standard ladder? ›

Protein ladders, also known as protein markers or protein standards, are used to help estimate the size of proteins separated during electrophoresis. They serve as points of reference because they contain mixtures of highly purified proteins with known molecular weights and characteristics.

Protein standards are mixtures of well-characterized natural or recombinant proteins that are loaded alongside protein samples in a gel. They are used to help monitor electrophoretic separation as well as estimate the size and concentration of the proteins separated in a gel.

Protein ladders or molecular weight markers are among the most commonly used reagents in biochemistry experiments. They provide molecular weight standards to estimate the size of proteins separated by gel electrophoresis like SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis).

Western blot protein ladders are designed for protein molecular weight estimation directly on the blot during detection. Consisting of recombinant proteins fused to an IgG binding site, these versatile molecular weight ladders bind the primary or secondary antibody used for the detection of the target protein.

The PageRuler™ Unstained Protein Ladder is a mixture of 14 recombinant, highly purified proteins ranging from 10 kDa to 200 kDa. For easy reference, the 50 kDa protein band has a greater intensity than the other proteins in the ladder.

A DNA ladder is a solution of DNA molecules of different lengths used in agarose or acrylamide gel electrophoresis. It is applied as a reference to estimate the size of unknown DNA molecules that were separated based on their mobility in an electrical field through the gel.

Transfer the desired amount of the Prestained Protein Ladder to a separate tube. For blotting: use 5 µl for mini-gels and 10 µl for full length gels. For visualizing during electrophoresis: use 10-15 µl for mini-gels and 20-30 µl for full length gels.

Unstained protein ladders are more accurate for sizing proteins, as the dyes used in prestained ladders can slightly distort the apparent size of the protein ladder proteins on the gel.

Because of being denatured and then coated in a negative charge, the proteins will migrate and separate based on size. To determine the size of the proteins, a molecular weight marker, or protein ladder, is used. Often, these ladders are pre-stained so you can visually detect the progress of the protein separation.

What is the difference between marker and ladder in gel electrophoresis? ›

These two terms mean essentially the same thing. DNA markers (and ladders) are DNA fragments of known length that are run in the same gel as unknown samples to provide a "marker" for where DNA fragments of particular lengths will migrate. Note that distance migrated is proportional to the log(MW) of the DNA fragment.

For a standard electrophoresis system, we recommend loading 0.5 µg (20 µl) of the Fast DNA Ladder on the agarose gel. For a fast electrophoresis system (5 to 30 minutes separation), follow the system's manufacturer recommendations: 5 to 20 µl load. A dilution of the ladder may be required.

A DNA ladder is a solution composed of DNA molecules of varying lengths. It is widely used in gel electrophoresis as a reference point or molecular-weight size marker to determine the approximate size of unknown DNA fragments.

A DNA ladder, also known as a molecular size marker or standard DNA marker, is a solution containing DNA fragments of varying lengths and sizes that serves as a reference in estimating the size of unknown DNA molecules after they are separated by agarose or acrylamide gel electrophoresis.

Protein ladders are composed of a series of bands, which are highly purified polypeptides of different well-defined sizes. These polypeptides get resolved during electrophoresis as separate bands - based on their molecular weights.