The proteins represent the entire predicted ectodomain of human cell surface proteins. Each protein is expressed by transient transfection in human HEK293 cells as an enzymatically monobiotinylated soluble protein. The proteins are purified, concentrations measured, quality-checked, normalised, and arrayed. We test our arrays for functional activity using a panel of binding probes of known specificity.

Proteins are expressed at varying levels spanning several orders of magnitude. Because the proteins on the array are secreted, we are able to measure their concentrations and normalise them before capturing them in individual wells. Importantly, this provides a constant experimental parameter which leads to clear binding signals.

All human type I, type II, GPI-anchored proteins are represented on the array including:

Cell adhesion and signalling proteins;

CD antigens

Many extracellular enzymes (glycosyltransferases, proteases, hydrolases, diesterases, phosphatases, peroxidases);

Virus receptors, parasite invasion receptors, microbial adhesion proteins for host-pathogen interactions;

Immunostimulatory and immunoinhibitory ligands, receptors and co-receptors;

Immunoglobulin and EGF superfamily domain family members.

Yes, we are able to present more complex protein architectures such as integrins (all 24 integrins are represented ), beta-2 microglobulin heterodimers (e.g. CD1, HLA-E, -F,  -G),  and homodimers (CTLA-4, CD28). 

We recommend screening your antibody of interest at a concentration of around 1 microgram per mL across the array.  For screens being carried out at Ectocellect, please provide a minimum of 50 micrograms of antibody, ideally at a concentration greater than 20 micrograms per mL, so that we can dilute it in our binding buffer. If your antibody is not limiting, then sending more is helpful as it provides a contingency.

We can accommodate both a product and service model. To perform the experiments yourself, ideally you will need appropriate fluid handling for 1536-well plates but get in touch if this is an issue for you. 

Please send your screening reagents to:

Ectocellect,

Department of Biology,

University of York,

Wentworth Way,

York YO10 5DD

United Kingdom

Yes.

We use a goat anti-human polyclonal secondary antibody that can detect all standard human IgG isotypes. We have found that this secondary antibody can detect antibodies that contain point mutations for silencing Fc receptor binding.

If your molecules are not in the standard human IgG format, you will need to get in touch about how we will detect binding. This could  include molecules such as:

Antibodies with non-human framework regions

Chimaeric antigen receptors (CARs)

Camelid nanobodies

If you are sending antibodies for screening at Ectocellect, we can provide an appropriate secondary antibody that is capable of detecting all endogenous human IgG  isotypes. We can also detect binding of IgA and IgM antibody isotypes. You can indicate which secondary antibody reagent we should use in a Samples Submission Sheet: a simple spreadsheet we will provide where you list your sample details. For anything more exotic, then please provide a validated secondary detection reagent with details for how it should be used.

Yes. The human receptor array is a highly adaptable and generic binding assay. The arrays have been successfully used to detect interactions between:

• Soluble recombinant proteins from a range of sources including humans, viruses, parasites, bacteria, fungi
• Intact virions
• Intact whole bacterial cells
• Intact whole mammalian cells.
• Human patient sera

We will provide the following information for each of your samples:

The raw unprocessed data provided as an image of the array with your binding probe. Here we use an example of an IgG1-formatted anti-CD80 antibody.

A graphical representation of the plate with the data analysed and identifying the positive targets.

A histogram of the analysed data, identifying the positive targets.

The human receptor array is composed of >1500 proteins found in the surfaces of human cells.  If your protein of interest is intracellular, secreted but not anchored to the cell surface, contains multiple transmembrane spans, or recognises a non-proteinaceous molecule, it is unlikely that your protein is present on the current version of the human receptor array.

We use the entire predicted extracellular region of the canonical protein isoform in the Uniprot database. Previous requests for specific isoforms are:

FCGR3A: The array has the “158F” (not “158V”) allele (rs396991)

Each array contains a number of positive controls that can be used to confirm the function of the arrays.

We can ship any unused samples back to you upon request, or will destroy them once the experiment is completed.