Extraction Kits Reagents

PROT20 FAQs

What is the Plasma Immunodepletion kit?
How does the kit work?
What is the major advantage of using protein depletion?
What makes the ProteoPrep 20 a superior depletion technique?
How much of the 20 most abundant proteins can be removed?
Is there a risk of losing some of the proteins that may be important for profiling protein expression?

What is the maximum amount of serum or plasma that can be loaded into the spin column?
Can the spin columns be re-used?
Can the kit be used for other sera or plasma?
What other applications or assays can benefit from plasma depletion?
What other products can be used in conjunction with this kit?
What happens if the media in the spin column dries up?


What is the Plasma Immunodepletion kit?
The ProteoPrep® 20 Plasma Immunodepletion Kit is a complete kit with all the necessary reagents and consumable supplies designed to specifically remove the 20 most abundant proteins from human plasma or serum.


How does the kit work?
Included in the kit are spin columns that are pre-packed with immunoaffinity media designed to specifically bind to the 20 most abundant proteins in human plasma or serum. When plasma or serum is loaded into the spin column, the 20 most abundant proteins are bound into the affinity media. The rest of the proteins do not bind to the column and are collected. The bound proteins are eluted with a special buffer and then collected separately. Multiple batches can be run on the same column and up to 300 µl of pooled eluates can be combined and concentrated for subsequent analysis.

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What is the major advantage of using protein depletion?
Removing the 20 most abundant proteins from plasma or serum enables the detection of low abundance proteins that are otherwise masked by the more abundant proteins. This is because the amount of sample loaded into the gel can be increased up to 50 times. Therefore, one can see more of the low abundance proteins that could not be detected otherwise.


What makes the ProteoPrep 20 a superior depletion technique?
The technology is based on a unique conjugation process using combined small recombinant immunoaffinity ligands and conventional antibodies that permit high-density multiplexed conjugation on the support. The ligand selection ensures optimal binding specificity and prevents contamination, and the high ligand density facilitates high binding capacity. More importantly, there is no comparable product that can efficiently deplete 20 of the most abundant proteins in one step!

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How much of the 20 most abundant proteins can be removed?
Our tests indicate that the kit removes 97-99% of the 20 most abundant proteins from human plasma or serum. To maximize depletion the serum eluate can be reloaded into the column (re-depleted).


Is there a risk of losing some of the proteins that may be important for profiling protein expression?
The immunoaffinity ligands and antibodies were carefully optimized for specificity to the 20 most abundant proteins. However, a small number of proteins, besides those specifically depleted, may bind to those proteins being depleted or on the medium. As a precaution, it is recommended to analyze also the bound proteins to confirm that the protein(s) of interest are not bound or lost.

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What is the maximum amount of serum or plasma that can be loaded into the spin column?
The immunoaffinity media has been optimized for 8 µl of serum or plasma. However, eluates from multiple runs can be pooled if necessary.


Can the spin columns be re-used?
Yes, the column can be re-used at least 100 times with proper cleaning and storage; however, after one year it is advisable to dispose the column because the integrity of the ligands can no longer be ascertained.

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Can the kit be used for other sera or plasma?
The immunoaffinity ligands and antibodies are optimized and are specific only for human sera or plasma. The specificity of the proteins from other species may be different and, therefore, will not bind efficiently to the immunoaffinity media. However, application of the kit to other human biological fluids may be worth exploring.


What other applications or assays can benefit from plasma depletion?
In addition to its wide use in gel electrophoresis for proteomic analysis, protein depletion can be utilized in HPLC chromatographic analysis, as well as for other functional assays.

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What other products can be used in conjunction with this kit?
This kit can be used for protein extracts from human tissues using the following products.


Product #  Product Name Add to Cart
PROTMEM ProteoPrep® Membrane Extraction Kit
PROTTWO ProteoPrep® Universal Extraction Kit
PROTTOT ProteoPrep® Total Extraction Sample Kit

It is also compatible with various detergents (44 Kb PDF) and protease inhibitors (1.1 Mb PDF).


What happens if the media in the spin column dries up?
The agarose affinity support is in the form of hydrogel beads and always needs to be hydrated or soaked in PBS buffer. In addition, the affinity ligands are proteins that need to be in the native conformation to be active in binding. If the column bed appears to be still intact, the column may be soaked overnight in Equilibration Buffer and then equilibrated using the prescribed procedure before use. However, if the column bead has collapsed or dried into a thin film, it should be discarded because there is no guarantee that full activity can be reconstituted after re-equilibration.







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