Detect, quantitate and analyze proteins
Protein detection, quantitation, and analysis are central to investigating a wide variety of biological processes. Measuring the protein concentration is necessary to processes ranging from protein purification and labeling to sample preparation for electrophoresis.
Protein quantification is the measurement of the total protein concentration in a sample. Protein can be quantitated directly via absorbance at 280 nm or indirectly using colorimetric (BCA, Bradford, etc.), or fluorometric methods offering advantages, such as greater sensitivity. To identify and measure a specific protein within a complex sample, for example, serum or cell lysate, an enzyme-linked immunosorbent assay (ELISA) may be used.
Cellular signaling and other biological processes may be analyzed using fluorescent proteins. For example, green fluorescent protein (GFP) can be expressed in living cells and used to visualize the localization and protein dynamics under experimental conditions. Tryptophan, an amino acid whose fluorescence emission properties are affected by its microenvironment, has also been used to gain information on changes in the conformational state of proteins.
Protein quantitation and analysis methods
Microplate readers with absorbance, fluorescence, and luminescence detection modes provide a versatile solution for the quantification and study of proteins. Our application notes demonstrate how these instruments can be used to obtain and analyze results.
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eBook: Nucleic acid & protein quantitation
Streamline absorbance assays for nucleic acid & protein quantitation
Absorbance microplate readers are widely used in basic research, drug discovery, bioassay validation, quality control, and manufacturing processes in pharmaceutical, biotech, food and beverage, and academic industries. These readers provide rapid and sensitive measurements of a variety of analytes across a wide range of concentrations for a wide range of assays, including ELISAs, microbial growth, detection of key compounds and contaminants, and protein quantitation.
eBook: Nucleic acid & protein quantitation
Streamline absorbance assays for nucleic acid & protein quantitation
Absorbance microplate readers are widely used in basic research, drug discovery, bioassay validation, quality control, and manufacturing processes in pharmaceutical, biotech, food and beverage, and academic industries. These readers provide rapid and sensitive measurements of a variety of analytes across a wide range of concentrations for a wide range of assays, including ELISAs, microbial growth, detection of key compounds and contaminants, and protein quantitation.
ELISA
Enzyme-linked immunosorbent assays (ELISAs) are used to measure the amount of a specific protein, using a microplate format, and results are most often detected via absorbance in the visible wavelength range. Chemiluminescent and fluorescent ELISA formats offer enhanced sensitivity for accurate quantitation of less abundant analytes.
ELISA
Enzyme-linked immunosorbent assays (ELISAs) are used to measure the amount of a specific protein, using a microplate format, and results are most often detected via absorbance in the visible wavelength range. Chemiluminescent and fluorescent ELISA formats offer enhanced sensitivity for accurate quantitation of less abundant analytes.
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Fluorescent protein applications
Proteins inside eukaryotic cells exist in a dynamic state, in a highly-regulated balance between synthesis and degradation. Whereas protein synthesis is well-understood after decades of study, major advances in our knowledge of protein degradation have occurred only in the last two decades. Fluorescent proteins can be used as reporters to investigate protein degradation and related cellular signaling pathways.
Learn more about how fluorescent proteasome sensors have been used in our application notes.
Fluorescent protein applications
Proteins inside eukaryotic cells exist in a dynamic state, in a highly-regulated balance between synthesis and degradation. Whereas protein synthesis is well-understood after decades of study, major advances in our knowledge of protein degradation have occurred only in the last two decades. Fluorescent proteins can be used as reporters to investigate protein degradation and related cellular signaling pathways.
Learn more about how fluorescent proteasome sensors have been used in our application notes.
IgG Quantification
In therapeutic protein engineering and cell line development, IgG quantification is the process of measuring the amount of immunoglobulin G (IgG), a common class of therapeutic proteins, produced by a genetically modified cell line. This is important for evaluating and monitoring the productivity of the cell line and selecting the best candidate for further development of therapeutic antibodies.
IgG Quantification
In therapeutic protein engineering and cell line development, IgG quantification is the process of measuring the amount of immunoglobulin G (IgG), a common class of therapeutic proteins, produced by a genetically modified cell line. This is important for evaluating and monitoring the productivity of the cell line and selecting the best candidate for further development of therapeutic antibodies.
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Measure protein concentration (Bradford, BCA, etc)
Protein concentration can be measured directly via absorbance at 280 nm in a UV spectrophotometer, or indirectly using colorimetric methods such as BCA or Bradford assays. Protein can even be quantitated using fluorometric methods.
Here are some application notes on protein quantitation you may find of interest:
- Streamline BCA-based protein quantitation on the SpectraMax iD5 reader
- Measure total protein in cell lysates with SpectraMax ABS Plus Microplate Reader
- Protein quantitation with the EMax Plus Microplate Reader
- Direct protein quantitation using the SpectraDrop Micro-Volume Microplate
- Using the NanoOrange Protein Kit with SpectraMax Microplate Readers
Measure protein concentration (Bradford, BCA, etc)
Protein concentration can be measured directly via absorbance at 280 nm in a UV spectrophotometer, or indirectly using colorimetric methods such as BCA or Bradford assays. Protein can even be quantitated using fluorometric methods.
Here are some application notes on protein quantitation you may find of interest:
- Streamline BCA-based protein quantitation on the SpectraMax iD5 reader
- Measure total protein in cell lysates with SpectraMax ABS Plus Microplate Reader
- Protein quantitation with the EMax Plus Microplate Reader
- Direct protein quantitation using the SpectraDrop Micro-Volume Microplate
- Using the NanoOrange Protein Kit with SpectraMax Microplate Readers
Tryptophan detection
The intrinsic fluorescence of proteins is due to the aromatic amino acids tryptophan, tyrosine, and phenylalanine. Tryptophan dominates the emission of proteins and is the most sensitive to solvent polarity and the local environment. Analysis of changes in tryptophan fluorescence can yield information on protein denaturation and conformation.
In these application notes, we demonstrate performance of the SpectraMax® multi-mode microplate readers for assays measuring intrinsic tryptophan fluorescence.
Tryptophan detection
The intrinsic fluorescence of proteins is due to the aromatic amino acids tryptophan, tyrosine, and phenylalanine. Tryptophan dominates the emission of proteins and is the most sensitive to solvent polarity and the local environment. Analysis of changes in tryptophan fluorescence can yield information on protein denaturation and conformation.
In these application notes, we demonstrate performance of the SpectraMax® multi-mode microplate readers for assays measuring intrinsic tryptophan fluorescence.
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Western blotting
Western blotting is a popular technique used for protein detection and quantitation. Learn about the various techniques used to detect proteins on western blot membranes including colorimetric, fluorescence, and chemiluminescence. We’ll also introduce you to a novel, first-of-its-kind western blot detection system on a multi-mode microplate reader.
Western blotting
Western blotting is a popular technique used for protein detection and quantitation. Learn about the various techniques used to detect proteins on western blot membranes including colorimetric, fluorescence, and chemiluminescence. We’ll also introduce you to a novel, first-of-its-kind western blot detection system on a multi-mode microplate reader.
Latest Resources
Resources for Protein quantitation and analysis
Brochure
QPix XE Microbial Colony Picker
QPix XE Microbial Colony Picker
Although smaller than other colony pickers on the market, don’t let its size fool you – it doesn’t compromise on results. The QPix XE streamlines your colony picking process, allowing you to…
Application Note
To achieve over 5 fold of human IgG protein detection signal enhancement with 1 round of CloneDetect K8495 assay optimization
To achieve over 5 fold of human IgG protein detection signal enhancement with 1 round of CloneDetect K8495 assay optimization
Protein G (Pro G) is a large cell surface binding protein that has a repeating 55-residue domain that binds with high affinity to the FC region of IgG. Together with Protein A (Pro A),…
Flyer
Quickly and easily quantify IgG with ValitaTiter
Quickly and easily quantify IgG with ValitaTiter
Integrating ValitaTiter and Molecular Devices fluorescence polarization (FP) plate readers produces a seamless IgG titer assay setup and optimization. Cell line development teams will realiz…
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Application Note
Spectral Fusion™ Illumination technology for an extended dynamic range on the SpectraMax i3x Multi-Mode Microplate Reader
Spectral Fusion™ Illumination technology for an extended dynamic range on the SpectraMax i3x Multi-Mode Microplate Reader
Many microplate readers and spectrophotometers use a photomultiplier tube (PMT) to detect fluorescence and luminescence signals. PMTs work by initially detecting photons from the sample…
eBook
Virology and Vaccine Research Microplate Reader Solutions
Virology and Vaccine Research Microplate Reader Solutions
We understand what a challenging time this is for those who are working to get accelerated testing and medicines to the market as soon as possible and are committed to supporting scientists…
Blog
COVID-19 Timeline: Diagnostics, Vaccines, and Therapeutic Antibody Development
COVID-19 Timeline: Diagnostics, Vaccines, and Therapeutic Antibody Development
Global research efforts are focused on understanding the SARS-CoV-2 virus in order to develop potential therapies for COVID-19. Join us as we explore a scientific timeline of key…
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eBook
The Ultimate Guide to Microplate Reader Solutions
The Ultimate Guide to Microplate Reader Solutions
Evaluating microplate readers doesn’t have to be overwhelming. First, consider your application needs. If your budget is modest, a single-mode reader dedicated to your main application may b…
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eBook
Streamline absorbance assays for nucleic acid & protein quantitation
Streamline absorbance assays for nucleic acid & protein quantitation
Absorbance microplate readers are widely used in basic research, drug discovery, bioassay validation, quality control, and manufacturing processes in pharmaceutical, biotech, food and bevera…
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Application Note
Measure total protein in cell lysates with SpectraMax ABS Plus Microplate Reader
Measure total protein in cell lysates with SpectraMax ABS Plus Microplate Reader
Quantification of protein concentrations from cell lysates is a key step for many downstream applications, such as western blots and enzyme-linked immunosorbent assays (ELISAs).
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Application Note
Streamline BCA-based protein quantitation on the SpectraMax iD5 reader
Streamline BCA-based protein quantitation on the SpectraMax iD5 reader
Learn how to quantitate a cellular protein sample with BCA protein assay kits on the SpectraMax® iD5 Multi-Mode Microplate Reader.
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Application Note
Measure intrinsic tryptophan fluorescence on the SpectraMax iD3 microplate reader
Measure intrinsic tryptophan fluorescence on the SpectraMax iD3 microplate reader
The intrinsic fluorescence of proteins is due to the aromatic amino acids tryptophan, tyrosine, and phenylalanine. Tryptophan, which excites maximally around 270-280 nm and has an emission…
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Application Note
Intrinsic tryptophan detection with the SpectraMax i3 Multi-Mode Microplate Platform
Intrinsic tryptophan detection with the SpectraMax i3 Multi-Mode Microplate Platform
The intrinsic fluorescence of proteins is due to the aromatic amino acids tryptophan, tyrosine, and phenylalanine. Tryptophan, which excites maximally around 270-280 nm and has an emission…
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Application Note
Using the NanoOrange Protein Kit with SpectraMax Microplate Readers
Using the NanoOrange Protein Kit with SpectraMax Microplate Readers
This application note describes how to use the NanoOrange® Protein Quantitation Kit from Life Technologies in SpectraMax® microplate readers with the fluorescence detection mode and SoftMax…
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Application Note
Protein quantitation with the EMax Plus Microplate Reader
Protein quantitation with the EMax Plus Microplate Reader
Endpoint readers are prolific in the laboratory since absorbance has become the detection of choice for many applications. Examples include ELISAs for quantitation of cytokines and protein…
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Application Note
Multiplexing Fluorescent and Chemiluminescent Live Cell Reporters to Dissect NFkB Signal Transduction Requirements
Multiplexing Fluorescent and Chemiluminescent Live Cell Reporters to Dissect NFkB Signal Transduction Requirements
The chemiluminescent Ready-To-Glow Secreted Metridia Luciferase reporter system from Clontech Laboratories was employed to monitor NFκB response element activation by TNF-a, and was…
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Application Note
Direct protein quantitation using the SpectraDrop Micro-Volume Microplate
Direct protein quantitation using the SpectraDrop Micro-Volume Microplate
Quantitation of protein using UV absorbance is a rapid, nondestructive method that relies on the absorbance of near-UV wavelengths of light by the tryptophan and tyrosine residues in a…
Scientific Poster
Measurement of Proteosome Inhibition in Live Cells on the Analyst® GT, FLEXstation® and Gemini EM Microplate Readers Using the BD Biosciences Proteasome Sensor
Measurement of Proteosome Inhibition in Live Cells on the Analyst® GT, FLEXstation® and Gemini EM Microplate Readers Using the BD Biosciences Proteasome Sensor
The proteasome is a massive protein complex inside all eukaryotic cells (and some bacteria) that removes unnecessary proteins by breaking them down into short peptides. It consists of a tunn…
