Protein microarray

Summary

  • Protein microarrays developed with our proprietary technology.
  • The quality of antibodies can be validated.
  • The binding and specificity of antibodies to antigens can be validated.
  • It is possible to search for antigens for antibodies with unknown antigens.
  • Predictive data for adverse effects can be obtained by validating the non-specific binding of antibody drugs.
  • Profiling of antibodies in human blood allows for the discovery of disease markers and drug targets.

Microarray imageMicroarray image

Click here for materials

System

  • Use of glass substrate
  • Two-color method

  • Comparison between samples is possible with normalization

Detectable antibodies

  • Human： IgG, IgA, IgM, IgE
  • Mouse： IgG, IgM, IgE
  • Rabbit： IgG

Required sample

  • Antibody: 20 μL (1 μg/μL sol. In PBS)
  • Serum, Plasma, Saliva: 100 μL

Notes

・ If the antibody concentration is low or the buffer solution contains glycerol, etc., please contact us.

・ Several biological samples can also be analyzed.

Human protein microarray

Our proprietary protein microarrays have a wide variety of research applications.

Microarray image

Two types of human protein microarrays are available.

Type 1

Proteins synthesized using wheat germ cell-free system

  • Over 16,000 human proteins on microarray
  • Rich in mutant proteins recognized in cancer.

・ It covers about 70% of all human genes.

・ Click here for a list of wheat germ cell-free lines.

Type 2

Proteins synthesized using cell-based expression system
(e.g., human cells, animal cells, and E. coli )

  • Over 5,000 human proteins on microarray

・ Click here for a list of expression systems except for wheat germ cell-free systems.

Antibody evaluation

  • Evaluation of target specificity
  • Antigen search for antibody
  • Evaluation of purification degree, etc.
Antibody binding to target proteins and cross-reactivity to other proteins can be validated.
React specifically to
target antigens		 Cross-react to
non-target antigens		 React specifically to
non-target antigens

Arrow(←): Target antigen

Profiling of antibodies in blood

  • Detection of autoantibodies
  • Biomarker search, etc.
Comparison of autoantibody profiling of sera from patients with rheumatoid arthritis

By comparing normalized data, characteristic autoantibodies of an individual or common among patients can be reproducibly detected.

Microbial protein microarray

Microbial proteins on protein microarray

  • Spot inactivated lysates and recombinant proteins from viruses (about 600), bacteria (about 1,200), fungi (about 90), protozoa (about 70), etc on microarray.
  • Analysis of reactions to 2,500 microbial antigens at once

Quality evaluation of anti-microbial antibodies

High specificity

Low specificity

Profiling of anti-microbial antibodies in blood

Profiling of blood antibodies in persons recovering from COVID-19

This is a profiling of serum IgG, IgM, and IgA in persons recovering from COVID-19. The type of antibodies to the proteins of the novel coronavirus in each individual can be characterized.
Most persons recovering from COVID-19 have antibodies against spike protein (*1).
On the other hand, only a few have IgG antibodies against RBD (*2).
(*1）A surface glycoprotein involved in viral entry into host cells.
(*2）A domain on the spike protein that binds to the host receptor ACE2. The domain is the recognition site for antibodies that confer neutralizing activity.


N: nucleocapsid protein, S: spike protein, ECD: extracellular domain excluding transmembrane domain, RBD: receptor binding domain

Profiling of anti-influenza virus antibodies in blood and evaluation of commercial antibodies

The type of antibodies to the virus strain in the sera of healthy individuals was evaluated.
The binding of the commercial antibodies to the viral strains was confirmed.

Immunomonitoring the microbiome
  • Confirms the presence of antibodies in blood to intestinal bacteria
  • Comprehensively capture the host side response

    • ・ Find the relationship with health condition.

    ・ Explore the relationship with pathological conditions

    ・ Explore changes over time in individuals


Columns indicate the respective sera and rows the respective microbial antigens.
Red: high binding　Blue: low binding
Percentage of positive spots
– IgG IgM IgA IgE
Virus 38 % 10 % 5 % 0 %
Bacteria 31 % 13 % 5 % 0 %
Fungi 29 % 28 % 10 % 0 %
■ Resources
Title File format
Human protein microarray (wheat germ cell-free system)※ Excel
Human protein microarray (cell-based expression system) Excel
Microbial protein microarray Excel
Summary of protein microarray PDF
Data analysis of protein microarray PDF
Leaflet PDF

※ The “Controls” sheet is a list of samples containing autoimmune disease-associated antigens in addition to false-positive causing antigens such as recombinant protein tags, various immunoglobulins, and nucleic acids.These samples are used to validate the experiment.

■ Reference

■ Identification of antigens recognized by salivary IgA using microbial protein microarrays. Hamuro et al., Biosci Microbiota Food Health, 41, 177-184 (2022)
https://www.jstage.jst.go.jp/article/bmfh/41/4/41_2022-014/_article/-char/en

■ A “ligand-targeting” peptide-drug conjugate: Targeted intracellular drug delivery by VEGF-binding helix-loop-helix peptides via receptor-mediated endocytosis. Michigami et al., PLoS One. 2021, 16, e0247045 (2021)
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0247045

■ Identification of autoantibodies using human proteome microarrays in patients with IPEX syndrome. Hoshino et al., Clin Immunol, 203, 9-13 (2019)
https://www.sciencedirect.com/science/article/abs/pii/S1521661618304662