Application Overview
[ABOVE] Figure 1.
Induction of JNK phosphorylation in response to LPS treatment. Phospho-JNK is shown in green, total JNK in red. Yellow indicates overlap in pseudocolor overlay.
Reprinted with permission from Bond, D.et al. Biol Proced Online. 10(1):20-28(2008)
For detection, replace your HRP-conjugated antibody with secondary antibodies labeled with IRDye infrared dyes.
Two protein targets can be detected in separate fluorescent channels, even if the bands co-migrate
Better image clarity for sharper, more detailed bands
Detect subtle mobility shifts caused by protein modifications such as phosphorylation
[ABOVE] Figure 2. Serial dilutions (10 ng to < 1 pg) of purified human transferrin (Tf) were used to assess Western sensitivity. The Odyssey Classic, using infrared fluorescence detection, reproducibly detected 1.2 pg of Tf, while only 4.9 -- 9.5 pg was detected with chemiluminescence. Infrared detection sensitivity was approximately 200-fold greater than previous studies with visible fluorophores (Cy®3, Cy®5, or FITC).
Advantages
Odyssey detection offers many general advantages over chemiluminescence:
Wide Linear Dynamic Range
Odyssey fluorescent detection provides the widest linear dynamic range, making
protein quantification simpler and more accurate
Western blot detection of Hsp70 is reported to be linear over 4.3 orders of magnitude,
from 5 pg to 100 ng1 (Figure 1)
Direct comparison demonstrates that Odyssey detection provides a greater dynamic range
than ECL chemiluminescence2 (Figure 1)
Compare against a concentration standard for absolute quantification2
Gather all the information you need from a single blot or image
[LEFT] Figure 1. Relationship between protein concentration of the hsp70 calibrant and fluorescence intensity. (a) Various concentrations of a hsp70 calibrant were assessed via western blotting. (b) There was a linear relationship between protein concentration and signal intensity across the full range from 5 pg to 100 ng – a range of 20,000 fold or 4.3 orders of magnitude.
Reprinted with permission from Bromage et. al. Marine Ecol. Prog. Ser. 376:123-132 (2009).
[ABOVE] Figure 2. Comparison of detection methods for Western blot analysis. Pure recombinant P53, Hdm2, and Hdmx protein samples of known concentration were serially diluted with 100 ng/ml BSA and run in duplicate on two gels, followed by Western blot analysis. Proteins were detected by using either LI-COR or standard ECL. Signal intensities from each Western blot were quantified by using either the LI-COR/Odyssey infrared image system or, for ECL, scanning the developed films, followed by analysis with Un-Scan-It software. Signal intensities were plotted against corresponding protein concentrations.
Reprinted with permission from: Wang, YV et al. Proc Natl Acad Sci USA. 104 (30): 12365-70 (2007) Copyright (2007) National Academy of Sciences, U.S.A.
Multiplexing
The Odyssey offers two independent channels (colors) for normalization or loading controls, so that two protein targets can be detected in separate fluorescent channels, even if the bands co-migrate.
[LEFT] Figure 1. Total EGF receptor (EGFR) and phospho-EGFR were detected simultaneously in lysates of unstimulated and EGF-stimulated A431 cells. Two fold serial dilutions of lysate were loaded. The single-color images can be merged to show both total and phospho-EGFR (yellow indicates overlap of red and green signals). The mobility shift caused by phosphorylation can be seen in the EGF-stimulated lysate (red signal above yellow band).
PubMed
Publishing with LI-COR data?
Odyssey® Publications, July - September 2011
- Expression levels and extent of phosphorylation of cell signaling proteins
- RNAi knockdown
- Activation of p53 (absolute protein quantification)
Wang et al employed quantitative Western blots on Odyssey to quantify levels of p53, Hdm2 and Hdmx proteins in exponentially growing human cell lines (WS1, fibroblast cells; 184V, mammary epithelial cells) and tumorigenic cell lines (MCF7, mammary epithelial cells; U2OS, osteosarcoma cells). Using pure p53 protein and N-terminally tagged Hdm2 and Hdmx proteins, they performed absolute quantification of the number of molecules/cell.
Wang, YV et al.
Quantitative analyses reveal the importance of regulated Hdmx degradation for p53 activation.
Proc Natl Acad Sci USA. 104(30): 12365-70 (2007)
- Validation of proteomic analysis
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