FAQ
Maybe you can find the answer to your question in our frequently asked questions forum.
What antigens are present on the array? Is my protein of interest on the array?
Our arrays contain more than 15,000 different human antigens with an unique proteome coverage, like full-length proteins, protein isoforms, peptides and neoantigens & frameshift peptides.
To explore different protein classes, tissue expressions or disease involvement please check our array content page.
To check if your protein of interest is expressed on the array, please download the complete gene finder file (xlsx, 19.3 MB), our database of all genes that are present on our hEXselect or UniPEx array.
Do I get qualitative or quantitative data?
We discriminate the intensity of detected hits between weak (1), medium (2) and strong (3). This spot intensity depends on the concentration of the antibody, but also on its affinity and the antigen concentration & presentation. Therefore, the hit intensity gives an indication of the quantity, but not exclusively, and therefore the results are to be assessed as qualitative.
To get an impression of results achieved with our arrays, have a look at our presentation of example results for biomarker discovery
How does it work? How much does it cost?
- Send us your sample (e. g. 50 µl serum). We set up the analysis according to your needs.
- We analyse your sample in-house. Our protein arrays based on E. coli clones spotted onto PVDF membrane express recombinant human proteins.
- Receive your evaluated results: analysis of interactions, antigen identification, scientific report, raw data. Discuss results with our experts, if desired.
- Validate your most promising candidates with our customized subarrays or receive information for follow-up research or translation into a clinical or diagnostic approach.
Full service package: 1,100 € per protein array (hEXselect or UniPEx array) + 560 € screening service per array + 1,000 € per order for result compilation.
Ask us for an individual offer, in which we can also consider a bulk discount. Email us
Are the proteins folded correctly?
It is technically not possible to ensure that all proteins are folded correctly. To present the expressed proteins on our array, the E. coli clones growing directly on the PVDF membrane are lysed under denaturing conditions. These are then changed to native conditions. Also, incubation conditions during the experiments are native. Therefore, it can be assumed that some proteins & peptides refold in parts or in their entirety in their native form, while others may remain in the denatured state.
How are engine protein arrays produced?
To produce engine protein arrays, E. coli expression clones are spotted onto a PVDF membrane, using our spotting robot Baloo. E. coli colonies grow and express the cloned human proteins directly on the membrane. After a defined time of protein expression, the arrays are processed E. coli lysis and fixation of proteins on the membrane and after dehydration, arrays are ready to use.
Watch the procedure of spotting in the video.
How likely are cross-reactivities with E. coli proteins?
We use E. coli clones with empty vectors, spotted on the PVDF membrane, as controls for unspecific bindings. An interaction (e.g. serum antibody binds to antigen) is considered positive (hit), if the signal-intensities of the clones in duplicate are clearly higher than the signal from the blank and empty vector controls. In this way, we can ensure that no non-specific binding activities are evaluated as false positives.
Can I pool my samples?
Samples can be pooled if desired. However, it should be considered that sample components of the individual samples may influence each other and the reaction with the antigen may be reduced. To achieve the best possible sensitivity, we therefore recommend single sample testing. If a sample pool is still desired, we offer pre-screening of the samples for potential pooling.
Can I get customized arrays?
Yes, we offer different customization of protein arrays. If your protein of interest is not present on the array, we offer different possibilities to spot your protein to the array as an additional service. If you need smaller arrays with fewer antigens for follow-up experiments to validate your biomarker candidates, we offer the manufacturing of subarrays with a size range from 500 up to 13,000 clones in duplicates.
Please contact us for further information on how we could support your project idea with customized protein arrays, prices can be discussed upon request. Email us
For which research areas can the arrays be used?
You can determine e. g. auto-antibody profiles of complex sera, cross-reactivity of antibodies (monoclonal, polyclonal, secondary) and protein-protein interaction pairs. Protein arrays are ideal for neurobiology, SARS-CoV‑2, cancer and autoimmune diseases, and many other fields of biomarker research.
Check if there are already a case studies of your research area in our publication database.
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