Introduction:
Discovery and validation of protein and peptide biomarkers in clinical proteomics requires large numbers of patient samples. Traditional methods are complicated, time-consuming and lack standardization. Peptide profiling with magnetic chromatography beads offers quick, reproducible screening and can be automated to run 96 samples in a day from start to finish. The method is reproducible and can be standardized, facilitating clinical and inter-laboratory collaborations.
Workflow:
The process is simple and you can easily capture proteins and peptides from complex samples such as serum, plasma and cerebrospinal fluid (CSF).
1. Incubate your sample with the Dynabeads® of choice
2. Use magnetic separation to quickly draw your target peptides to the tube/well wall
3. Wash, then elute peptides off the beads
4. Perform mass spectrometry and analyze the results.
Once you have screened the sample you can use columns to perform an in-depth screening. Not only will you conserve your precious samples, you can save months of valuable research time.
Feature:
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Capture peptides directly from serum/plasma for mass spectrometry, Quick, reproducible screening of peptides
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Screen 96 samples in 27 hours
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Consistency between lots secures comparable results
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Can be standardized
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Analyze large numbers of samples simultaneously
Application:
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Analysis of all peptides in tissue sample or body fluid (peak pattern)
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Comparison of peptides in different samples (differential peptidomics)
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Identification of peptides by tandem MS for species whose genome is known
Multiple Surface Screening:
Multiple Surface Screening of Serum Samples increases the number of ion peaks observed in a sample. Serum peptide profiling was performed with Dynabeads® RPC 18, Dynabeads® SAX and Dynabeads® SCX using a single serum sample. Aliquots of eluted peptides were analyzed by MALDI-TOF mass spectrometry and typical spectra were produced. Fig. 1 shows that distinct spectra are obtained from a single serum sample for each bead type.
Peak lists were compared and the Venn diagram shows percentages of the total ion count for all samples, see Fig. 2.
By using different combinations of Dynabeads® you widen the range of visible ion peaks, increasing the certainty of finding the target peptides that you are searching for.
Table 2 - Reproducibility between lots gives results you can trust
Reproducible Results - Use in combination or alone:
Reproducibility You Can Trust!
Each of the Dynabeads® magnetic chromatography products will give you reproducible spectra because the variation between lots is very low. This table shows the variation in ion peak number per spectrum for serum profiling using three different lots of Dynabeads® RPC 18. In total 40 analyses were performed for each lot using a single serum sample. Aliquots of eluted peptides were analyzed by MALDI-TOF mass spectrometry.
As clinical trials/studies take time to complete, using a reproducible, reliable method such as this allows for inter-laboratory studies.
Figure 3. Consistent beads
give consistent results Serum peptide profiling
was done using Dynabeads® RPC 18 and an
alternative method. 80 analyses were performed
for each product using a single serum sample.
Aliquots of eluted peptides were analysed by
MALDI-TOF mass spectrometry, followed by
Principal Component Analysis of normalized
profiles Fig. 3. Less analytical variation is
seen with Dynabeads® RPC 18.
Reference:
1. J Villanueva, K Lawlor, R Toledo-Crow and P Tempst (2006) Automated serum peptide profiling. FNature Protocols, Vol 1, No.2. 880-891.
2. CR Jimenez, ZE Filali, JC. Knol, K Hoekman, FAE Kruyt, G Giaccone, AB Smit and KW Li (2007) Automated serum peptide profiling using novel magnetic C18 beads off-line coupled to MALDI-TOF-MS. Proteomics Clin. Applications 1(6):598-604.
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