What are CelluSpots™ peptide arrays?
CelluSpots™ are custom arrays of peptide-cellulose conjugates spotted on planar surfaces in microscope slide format. Peptides are synthesized on a modified cellulose support which will be dissolved after synthesis. The solutions of individual peptides covalently linked to macromolecular cellulose are then spotted onto surface of choice.

What are the applications of peptide arrays?
CelluSpots™ peptide arrays are a convenient tool for the detection of interaction partners with defined amino acid sequences that are presented on the chip surface. Some of the typical applications are: analysis of protein-protein interactions, enzyme activities (e.g. kinases), receptor-ligand interactions and epitope mapping.

How many CelluSpots™ arrays can I order from one initial synthesis?
From one initial synthesis hundreds of identical slides can be produced. CelluSpots™ arrays of the same synthesis can be reordered at a more favourable price even one year after the first purchase as the peptide-cellulose-conjugates are kept at -20°C until re-spotting.

What is the standard surface of CelluSpots™?
As standard surface glass slides (76x26 mm or 75x25 mm) covered with inert white background foil are used.

What layout have CelluSpots™ arrays?
Standard CelluSpots™ arrays contain four blocks, each with 192 spots, surrounded by red colour marks. In total up to 384 peptide-conjugates with a spot-to-spot distance of 1.2 mm can be spotted in duplicate on one slide. The diameter of one spot is approximately 0.7 to 1 mm. Other formats are available upon request.

How can I incubate my arrays?
Incubation can be done under a cover slip or with slightly larger volumes in appropriate chambers on an orbital shaker. The latter alternative might give better signal intensities due to agitation during the incubation time.

What detection methods can be used for CelluSpots™ peptide arrays?
Standard slides with white inert surface can be used for detection in combination with chemiluminescence substrates, standard chromogenic substrates or autoradiography.

Which enzyme based detection methods are compatible with CelluSpots™ arrays?
Two of the most common enzyme-conjugates used for detection are alkaline phosphatase (AP) and horseradish peroxidase (HRP). Both can be used for the analysis of CelluSpots™ arrays. Other methods should work as well.

Are single spots on CelluSpots™ arrays visible by eye?
The single spots have a diameter of approx. 1 mm and can be seen by eye. All peptide-conjugates spots are surrounded by red coloured spots as orientation marks.

How can I analyse the CelluSpots arrays?
To use them for computer analysis software you can scan them by a common flat bed scanner. We will deliver an excel file together with the CelluSpots arrays that enable you to locate the peptide-sequences on the spots and the other way round. Please take a look at the attached example file. If you click on positions of the array scheme you will see the peptide at this position. Next to the peptide is an red arrow that will bring you back to the scheme.

How are CelluSpots™ arrays supplied?
20 peptide arrays are delivered in 5 packs of 4 CelluSpots™ arrays (plastic boxes).

How should CelluSpots™ arrays be stored?
For better stability the peptide arrays should be stored at 4°C (for few days to weeks) or at -20°C for long term storage (month).

Can I reuse the same CelluSpots™ array?
To get reliable results each array should only be used once. We have not tested to reuse CelluSpots™ arrays and will not give any guarantee for the reusability of arrays.

How are the peptides bound to the support?
The peptides are bound to modified macromolecular cellulose via their C-terminus. Peptide-cellulose-conjugates are spotted onto slides. After evaporation of the solvent a three-dimensional layer is formed which will not dissolve in aqueous reagents used for standard assays.

Should the N-terminus be acetylated?
Acetylated peptides are more stable to degradation. If peptides on the array are representing complete protein or parts of protein sequences, their N-terminal end should be acetylated because this uncharged state – acetylated peptides do not have charged amino functions (NH3+) at their N-terminus – represents better an internal part of a protein.

What modifications can be used for synthesis of peptide-conjugates?
Some modifications of peptide-conjugates for CelluSpots™ arrays include unnatural amino acids like D forms, phosphorylated amino acids or biotinylation. Other modifications are available upon request.

Can I use internal controls on my CelluSpots™ array?
Yes, there are several possibilities for controls on your array. Good controls are e.g. peptide tags for defined antibodies like c-MYC, V5, VSV-G or HA tags or peptides with a terminal biotin or streptavidin binding sequences.

What peptide length do you recommend?
As most linear epitopes have a length of 4-9 amino acids, we recommend peptides with a length of 12 to 18 residues and an offset of 2 to 5 amino acids. For fine mapping of the epitopes peptides varying in length with an offset of one amino acid can be used.