Scientists construct precise arrays of virus particles toward more efficient diagnostic assays

February 14, 2014, RIKEN
Figure 1: Electron microscopy image of measles virus particles firmly attached to the surface of a slide with a photoreactive polymer. Credit: Sivakumar et al.

Antibodies in the bloodstream hold the history of a patient's past infections. Clinicians probe this history by immobilizing protein particles or proteins of clinical interest onto the plastic surface of an assay plate and looking for antibodies that 'stick' to those targets after incubation with a serum sample. Yoshihiro Ito and colleagues from the RIKEN Center for Emergent Matter Science have now devised a superior assay that allows researchers and clinicians to obtain such diagnostic information more efficiently.

For some time now, scientists have been detecting DNA using 'microarrays'—glass slides featuring immense numbers of precisely positioned spots, each containing a different target sequence of interest. Unfortunately, translating this approach for has been problematic. "DNA is made of only four bases and the range of chemical functional groups is very limited," says Ito. "But proteins are composed of 20 amino acids with many chemical , which makes it difficult to immobilize different proteins on the same surface using a single method."

Ito and his colleagues found some success with photo-immobilization, in which proteins are mixed with polymers that essentially turn into 'glue' when bombarded with ultraviolet (UV) light. However, as existing polymers are poorly suited for whole virus particles, the team embarked on a search for a superior photo-immobilization medium. The search pointed to photoreactive polyethylene glycol (PEG), which offers numerous advantages. Notably, PEG forms a layer on the slide surface that resists binding by nontarget molecules, thereby yielding more accurate assay results. PEG also responds to lower levels of irradiation, minimizing the risk of UV damage to bound proteins or viruses.

After confirming that the photoreactive PEG layer can successfully affix (Fig. 1), the researchers developed an automated workflow that enabled them to analyze antibody binding from tiny volumes of patient serum on a microarray in just 20 minutes. By comparison, a standard plate-based assay requires far more serum and takes a few hours to complete. The tests also showed essentially equivalent performances in analyzing patient for five different viruses, with a false-negative rate lower than 5 per cent in most cases.

The system is now undergoing further development with the RIKEN venture company Consonal Biotechnologies and Ito sees great potential for rapidly testing a larger number of samples against a greater number of targets. "Our system achieves short detection times with small amounts of blood," he says. "We hope to contribute to society by commercializing this useful system."

Explore further: Improving human immunity to malaria

More information: Sivakumar, P. M., Moritsugu, N., Obuse, S., Isoshima, T., Tashiro, H. & Ito, Y. "Novel microarrays for simultaneous serodiagnosis of multiple antiviral antibodies." PLoS ONE 8, e81726 (2013). dx.doi.org/10.1371/journal.pone.0081726

Related Stories

Improving human immunity to malaria

August 1, 2012
The deadliest form of malaria is caused the protozoan Plasmodium falciparum. During its life-cycle in human blood, the parasite P. falciparum expresses unique proteins on the surface on infected blood cells.

Probing changes to infant milk formulations

January 22, 2014
Infant milk formula is a widely accepted alternative to breast milk for babies in their first year of life. Since breast milk contains all the nutrients required by young infants, formula manufacturers aim to closely match ...

Scientists find mechanism that helps HIV evade antibodies, stabilize key proteins

February 3, 2014
NIH scientists have discovered a mechanism involved in stabilizing key HIV proteins and thereby concealing sites where some of the most powerful HIV neutralizing antibodies bind, findings with potential implications for HIV ...

Scientists create potential vaccine against respiratory syncytial virus

February 5, 2014
Scientists at The Scripps Research Institute (TSRI) have invented a new method for designing artificial proteins, and have used it to make key ingredients for a candidate vaccine against a dangerous virus, respiratory syncytial ...

Recommended for you

Everything big data claims to know about you could be wrong

June 19, 2018
When it comes to understanding what makes people tick—and get sick—medical science has long assumed that the bigger the sample of human subjects, the better. But new research led by UC Berkeley suggests this big-data ...

Are you sticking to your diet? Scientists may be able to tell from a blood sample

June 19, 2018
An analysis of small molecules called "metabolites" in a blood sample may be used to determine whether a person is following a prescribed diet, scientists at Johns Hopkins Bloomberg School of Public Health have shown.

Diagnosing and treating disorders of early sex development

June 19, 2018
Diagnosing, advising on and treating disorders of early sex development represent a huge medical challenge, both for those affected and for treating physicians. In contrast to the earlier view, DSD (Difference of Sex Development) ...

BPA can induce multigenerational effects on ability to communicate

June 18, 2018
Past studies have shown that biparental care of offspring can be affected negatively when females and males are exposed to bisphenol A (BPA); however, previous studies have not characterized how long-term effects of BPA exposure ...

New compound shown to be as effective as FDA-approved drugs against life-threatening infections

June 15, 2018
Purdue University researchers have identified  a new compound that in preliminary testing has shown itself to be as effective as antibiotics approved by the Food and Drug Administration to treat life-threatening infections ...

Foods combining fats and carbohydrates more rewarding than foods with just fats or carbs

June 14, 2018
Researchers show that the reward center of the brain values foods high in both fat and carbohydrates—i.e., many processed foods—more than foods containing only fat or only carbs. A study of 206 adults, to appear June ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.