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Pierce™ His Protein Interaction Pull-Down Kit (Thermo Scientific™)

Thermo Fisher Scientific Pierce His Tag Protein Interaction Pull-Down Kit contains the necessary components to capture and purify proteins that interact with His-tagged fusion proteins.

Features of His Tag Protein Interaction Pull-Down Kit:

6xHis pull-down (Product No. 21277)—purifies protein interactors of any His-tagged fusion protein
Complete kits—provide all components and detailed protocol for purifying protein:protein interactions
No special equipment needed—use common laboratory equipment and reagents (e.g., microcentrifuge)
Convenient—microcentrifuge spin columns facilitate simple and efficient manipulation of agarose beads, including simple processing of multiple samples
Flexible—instructions include protocols for use with bait and prey proteins expressed from a variety of sample types
Less non-specific binding—Cobalt chelate resin is more specific for histidine-tagged fusion proteins than nickel resins, resulting in less non-specific binding
Binding—Binds 10 to 25 mg of histidine-tagged fusion protein per mL of resin


• Discover a new protein:protein interaction from a cell lysate
• Confirm a putative interaction from a cell lysate or with a previously purified protein
• Extract protein:protein interaction information from in vitro transcription/translation lysates

You provide the tagged fusion protein as the "bait" and the cells expressing the putative protein interaction target ("prey"), and the Pull-Down Kits provide everything else: cell lysis buffer, microcentrifuge spin columns, tag-specific affinity resin (agarose beads) and optimized buffers and protocol. The Pull-Down Kits are designed to teach the method to first-time users and to increase ease-of-use, convenience and reproducibility for experienced researchers.

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ProteinSEQ™ Protein A Core Kit (Applied Biosystems™)

The ProteinSEQ™ Protein A Core Kit is a partial kit that enables users to customize their ProteinSEQ protein measurements for leeched Protein A, or any other ligand used in their purification columns. It contains the buffers and reagents, but not the antibody-loaded capture beads, needed to enable PCR-based quantitation of Protein A or any other purification ligand. The kit contains sufficient reagents for 200 reactions. For a kit that includes Protein A capture beads and standards, for use in the quantitation of Protein A, please see the ProteinSEQ™ Protein A Quantitation Kit (Cat. No. 4469343).

• Quantitate leeched protein contaminants with ultra-high sensitivity
• Accelerate process development with more valid test results per run
• Reduce assay hands-on time with less sample dilution and preparation
• Achieve unprecedented productivity with near-5-log assay dynamic range

ProteinSEQ Protein A quantitation
The ProteinSEQ assay platform uses qPCR technology to measure process contaminants with extraordinary sensitivity and unparalleled dynamic range. Protein A or other purification ligands leeching from purification columns can be accurately measured with outstanding spike recovery and dilutional linearity.

Streamlined assay worflow
The ProteinSEQ system is the only instrument platform-based Protein A and purification ligand quantitation solution to offer single-digit picogram sensitivity and nearly 5 logs of dynamic range. Laboratory workflow is greatly accelerated due to the reduction in the number of sample dilutions and replicates in each run.

SphingoStrips™ Membranes (Invitrogen™)

SpingoStrips™ membranes are designed for the identification of proteins possessing phosphoinositide or sphingolipid recognition domains and for analysis of their lipid-binding specificities.

Pierce Plant Total Protein Extraction Kit (Thermo Scientific™)

The Thermo Scientific Pierce Plant Total Protein Extraction Kit effectively extracts protein from all kinds of dry and fresh plant tissue without liquid nitrogen or organic solvents.

Features of the Plant Total Protein Extraction Kit:
Efficient—obtain excellent protein yields in less than 10 minutes using a single buffer and a spin column
Versatile—native or denaturing lysis buffers for protein extraction from leaves, stems, and seeds
Compatible—extracts can be quantified using the BCA Protein Assay Kit or the Rapid Gold BCA Protein Assay Kit

The Pierce Plant Total Protein Extraction Kit is composed of optimized buffers and filter cartridges that allow for efficient and rapid protein extraction in less than 10 minutes. The kit is designed to rapidly extract denatured or native proteins from plant tissues (leaves, seeds, soft stem, roots, etc.). Simply grind the sample in the lysis buffer in the filter cartridge and centrifuge. The protein extracts can be used for applications such as SDS-PAGE, western blotting, immunoprecipitation, affinity purification, and activity assays.

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LightShift™ Poly (dI-dC) (Thermo Scientific™)

Thermo Scientific LightShift Poly(dI-dC) can be used as competitor for nonspecific DNA binding proteins.

More Product Data
Transfer EMSA gels using the Pierce G2 Fast Blotter

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Quant-iT™ Protein Assay Kit (Invitrogen™)

The Quant-iT Protein Assay Kit makes protein quantitation easy and accurate. The kit provides concentrated assay reagent, dilution buffer, and pre-diluted BSA standards. Simply dilute the reagent, load it into the wells of a microplate, add 1-20 µL of sample, mix, then measure the fluorescence. The assay is highly selective for protein and exhibits very little protein-to-protein variation. The assay is performed at room temperature, and the signal is stable for 3 hours. Common contaminants, such as salts, solvents, or DNA—but not detergents—are well tolerated in the assay. Quant-iT DNA Assay Kits (Q33120, Q33130) and a Quant-iT RNA Assay Kit (Q33140) are also available.

Pro-Detect™ Rapid AVI Competitive Assay Kit (Thermo Scientific™)

The Thermo Scientific Pro-Detect Rapid AVI Competitive Assay Kit is a single-use, dipstick lateral flow kit for quick, easy detection of AVI (sequence: GLNDIFEAQKIEWHE)-tagged proteins in protein expression and purification systems. This lateral flow assay uses membrane-based strips coated with dye-bound conjugated antibodies specific to AVI tag to provide a qualitative detection within ten minutes. This assay can be used to detect AVI-tagged proteins directly from cell culture media (supernatant) or cell lysates without any special instrumentation or handling.

Features of the Pro-Detect Rapid competitive assay kits:
Easy to adopt—lateral flow strips can be used early in and throughout expression to monitor and confirm expression of desired protein-tagged target
Simple, fast method—simply dilute sample using provided diluent and dip in the lateral flow strip for qualitative results within 5-10 minutes
Sensitive—detect protein tags in supernatant or cell lysate samples down to low µg/mL concentrations
Specific—assay does not cross-react with common lysis and protein preparation reagents
Reliable—results are similar to other antibody immunoassays, including western blot and ELISA
Long shelf life—stable for at least one year at 4°C

Each Pro-Detect Rapid competitive assay is performed by simply adding a properly diluted tissue culture supernatant, lysate, or purified protein sample to a test tube or microplate well and dipping in a lateral flow strip. Gold-conjugated detection antibodies embedded in the strip form complexes with the tagged protein in the sample. In the presence of target protein tag, the dye-bound conjugated antibodies will bind to the tagged protein present in the sample instead of the protein tag bound at the test lines. Therefore, in a positive result, a competitive lateral flow assay will show decreasing intensity of the visible test lines until all test lines have disappeared. When there is no target protein tag present, the dye-bound conjugated antibodies specific to the target will bind at the test line(s), resulting in visual test lines in a negative result.

PIP Strips™ Membranes (Invitrogen™)

PIP Strips™ membranes are designed for the identification of proteins possessing phosphoinositide domains and for analysis of their lipid-binding specificities. PIP Strips™ membranes facilitate the analysis of phosphoinositide protein interactions by protein-lipid overlay assays. Proteins may be detected using standard western blot procedures in conjunction with high-performance alkaline phosphatase- and horseradish peroxidase (HRP)-mediated signal generation systems.

Pierce™ Co-Immunoprecipitation Kit (Thermo Scientific™)

The Thermo Scientific Pierce Co-Immunoprecipitation Kit provides covalent antibody immobilization and all the components necessary to perform a properly controlled co-IP experiment without antibody interference in the final product.

Co-IP is a common approach to study protein:protein interactions that uses an antibody to immunoprecipitate the antigen (bait protein) and co-immunoprecipitate any interacting proteins (prey proteins). Traditional co-IP methods that use Protein A or G result in co-elution of the antibody heavy and light chains that may co-migrate with relevant bands, masking important results. The Pierce Co-IP Kit resolves this issue by covalently coupling antibodies onto an amine-reactive resin. The kit includes optimized buffers for protein binding and recovery, reagents to perform control experiments and efficient spin columns and collection tubes, which shorten the protocol and minimize handling and mixing.

Features of the Co-Immunoprecipitation Kit:

Works for any purified antibody—perform co-IP experiments using any purified antibody regardless of species or Ig class (chicken IgY, human IgE, mouse IgG1, IgM, etc.); no dependence on Protein A and Protein G affinity binding
No antibody interference—covalent attachment method and non-reducing elution system yields pure co-IP products without contamination by the IP antibody
Reusable antibody beads—covalent antibody immobilization allows prepared IP resin to be reused and provides potential savings of costly antibody
Complete kit—all reagents for antibody immobilization and many IP experiments, including binding and wash buffers, elution buffer and convenient microcentrifuge spin columns to make resin manipulations easier and more efficient.
Control beads included—underivatized agarose beads provided for use as negative control for nonspecific binding
Versatile—co-IP method is compatible with any physiolgical (non-denaturing) protein sample buffer that is compatible with the specific antibody-antigen and protein interaction complex.

Co-immunoprecipitation (Co-IP) is a popular in-vitro method for discovering protein interactions. The Pierce Co-Immunoprecipitation Kit is configured to provide the essential tools to effectively perform Co-IP experiments in a manner that yields pure IP and co-IP products free of troublesome IP antibody. This improvement on the traditional co-IP technique is achieved by replacing Protein A/G agarose beads with AminoLink Plus Resin to which pure IP antibodies can be directly and permanently conjugated. Gentle (non-reducing, non-denaturing) elution buffer allows dissociation of the IP targets while retaining the immobilized antibody on the agarose beads. The result is a pure product that can be analyzed by Western blotting (or even sequenced) without interference from antibody.

In addition to eliminating IP antibody contamination, the antibody-conjugation method integral to the Pierce Co-IP Kit avoids non-specific binding interactions and leaching contamination that can result from traditional Protein A and Protein G methods. Although the conjugation method requires that the starting antibody be in an amine-free buffer without BSA, gelatin or other storage protein stabilizers, the fact that it does not depend on Protein A or Protein G means that any antibody species or class can be used for IP (e.g., IgM and chicken IgY). Indeed any purified protein can be immobilized for use in affinity purification of binding partners.

Pierce™ Quantitative Peroxide Assay Kit (Lipid) (Thermo Scientific™)

The Thermo Scientific Pierce Quantitative Peroxide Assay Kit (lipid-compatible formulation) detects and measures hydrogen peroxide levels in biological samples using an iron and xylenol orange (XO) reagent.

This lipid-compatible peroxide assay kit detects peroxides based on oxidation of ferrous to ferric ion in the presence of xylenol orange. The kit's formulation may be used with lipid-containing samples without first extracting the lipids; however, because this kit does not contain sorbitol, the assay is less sensitive. Most proteins do not interfere with this assay, although some metal chelators may require use of a blank (i.e., control) to mitigate these effects.

Features of the Quantitative Peroxide Assay Kit:

Peroxides—detects and measures hydrogen peroxide (H2O2) levels in biological and other liquids samples
Convenient—no proprietary reagents involved but the ready-to-use kit removes the variability, difficulty and added expense of formulating the reagents yourself

• General hydrogen peroxide (H2O2) measurement in protein samples
• Quantitation of peroxides in detergents
• Assessment of the effects of peroxides on cellular activity
• Determination of protein glycation; Measurement of peroxide accumulation in lipids

In this assay, hydroperoxides convert the Fe2+ to Fe3+ at acidic pH. With this lipid-compatible formulation, the peroxide converts the Fe2+ to Fe3+ directly. In a sulfuric acid solution, the Fe3+ complexes with the xylenol orange (XO) dye to yield a purple product having an absorbance maximum at 560nm. Peroxide levels in test samples can be determined by calculation from the known extinction coefficient of the XO-Fe complex or by reference to a standard curve prepared with hydrogen peroxide solution.

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Pierce™ Glycoprotein Carbohydrate Estimation Kit (Thermo Scientific™)

The Thermo Scientific Pierce Glycoprotein Carbohydrate Estimation Kit enables the amount of protein glycosylation to be measured as the percent of total purified protein mass.

Features of the Glycoprotein Carbohydrate Estimation Kit:

Qualitative—easily identifies purified proteins as glycoproteins or samples as contaminated with sugars
Semi-quantitative—estimates the percent carbohydrate content (w/w) of purified glycoprotein by comparison to the included set of glycoprotein standards
Simple procedure—completed in less than 75 minutes; instructions include microplate and test tube protocols
Adaptable—standard curve format allows for the design of alternative tests for aldehydes and carbohydrate components

The Glycoprotein Carbohydrate Estimation Kit includes six purified glycoprotein standards and the required assay reagents to effectively estimate the amount of oxidizable glycosylation (percent carbohydrate by weight) of purified protein samples. Sugar groups in the glycoprotein sample are first oxidized with sodium meta-periodate to produce detectable aldehyde groups. Then the sample is reacted with the colorimetric Glycoprotein Detection Reagent. Absorbance at 550 nm of the resulting purple reaction product is measured with a spectrophotometer or plate reader. Finally, the carbohydrate content in the glycoprotein is calculated by comparison to results from the five glycoprotein standards that are included in the kit.

• Determine if a purified polyclonal antibody or other protein is glycosylated before attempting to perform carbohydrate-based conjugation or immobilization chemistries with hydrazide reagents
• Characterize and classify purified protein fractions from an affinity procedure
• Assess sugar and carbohydrate contamination in non-glycosylated protein samples

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LightShift™ EMSA Optimization and Control Kit (Thermo Scientific™)

The Thermo Scientific LightShift EMSA Optimization and Control Kit is an extraordinarily robust and sensitive system for performing electrophoretic mobility shift assays (EMSA) to identify and characterize protein-DNA binding interactions. The kit includes reagents for setting up and customizing DNA binding reactions and a control set of DNA and protein extract to test the kit system.

Features of theLightShift EMSA Optimization and Control Kit:

• Excellent for detecting low-abundance proteins in nuclear extracts
• Sensitivity that surpasses radioactive and digoxigenin methods
• Compatible with previously established binding conditions for popular DNA-protein interactions
• Includes EBNA control system to help new users develop a working assay and understand the methods used to confirm binding interaction specificity

The principle for LightShift EMSA Detection is similar to a Western blot. Biotin end-labeled duplex DNA is incubated with a nuclear extract or purified factor and electrophoresed on a native gel. The DNA is then rapidly (30 minutes) transferred to a positive nylon membrane, UV crosslinked, probed with streptavidin-HRP conjugate and incubated with the substrate. The protocol from labeling to results can be accomplished in a single day.

The interaction of proteins with DNA is central to the control of many cellular processes including DNA replication, recombination and repair, transcription, and viral assembly. One technique that is central to studying gene regulation and determining protein:DNA interactions is the electrophoretic mobility shift assay (EMSA).

The EMSA technique is based on the observation that protein:DNA complexes migrate more slowly than free DNA molecules when subjected to non-denaturing polyacrylamide or agarose gel electrophoresis. Because the rate of DNA migration is shifted or retarded upon protein binding, the assay is also referred to as a gel shift or gel retardation assay. Until conception of the EMSA protein:DNA interactions were studied primarily by nitrocellulose filter-binding assays.

All that is needed to perform the assay is purified DNA target that has been end-labeled with biotin, the protein extract to be tested, nylon membrane and basic electrophoresis equipment. DNA targets can be synthesized with 5' or 3' biotin labels or they can be labeled after synthesis using the Thermo Scientific Biotin 3' End DNA Labeling Kit (Product No. 89818). Nuclear, cytosolic or whole cell protein extracts can be obtained by a variety of methods, including the Thermo Scientific NE-PER Nuclear and Cytoplasmic Extraction Reagent Kit (Product No. 78833).

More Product Data
Transfer EMSA gels using the Pierce G2 Fast Blotter

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Pierce™ BCA Solid (Thermo Scientific™)

Thermo Scientific BCA (bicinchonic acid) is for use in BCA protein assays for the determination of protein concentration.

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InsuQuant Mass Spectrometric Kit (Thermo Scientific™)

Simplify your affinity purification workflow with the Thermo Scientific™ InsuQuant™ Mass Spectrometric Kit, an exclusive pre-analytical solution designed to simultaneously detect, differentiate, and quantify endogenous and exogenous insulin types.

Qubit™ Protein Assay Kit (Invitrogen™)

The Qubit Protein Assay Kit is designed specifically for use with the Qubit Fluorometer. Using between 1 and 20 µl of your sample, this assay can quantitate samples ranging from 12.5 µg⁄ml to 5 mg⁄ml and exhibits low protein to protein variation. The assay is highly selective for proteins and is designed to be accurate in the presence of reducing reagents, but not in the presence of a large amount of detergent. Common contaminants, such as reducing reagents (DTT, β-mercaptoethanol), salts, free nucleotides, amino acids, solvents, or DNA, but not detergents, are well tolerated in the assay. Slight protocol modifications are required for other contaminants. The kit provides concentrated assay reagent, dilution buffer, and pre-diluted BSA standards. Simply dilute the reagent using the buffer provided, add your sample (any volume between 1 µL and 20 µL is acceptable), and read the concentration.

Which product to choose for fluorometric protein quantitation?
• For 1–20 samples: use this Qubit Protein Assay Kit with the Qubit Fluorometer
• For 20–2000 samples: use the Quant-iT Protein Assay Kit with microplate reader

1. All Qubit assay kits can be used with the Qubit 1.0, Qubit 2.0, Qubit 3, and Qubit 4 fluorometers.
2. 500 µL thin-walled PCR tubes are required but not included.