omation mbers - Society for Laboratory Automation and Screening

3:30 pm Wednesday, February 4 Proteomics – Technology 1 Room B1
Judith Finlay
Beckman Coulter
7330 Carroll Road
San Diego, California 92121
jafinlay@beckman.com
88
Co-Author(s)
Carlton Gasior, Chad Pittman, Melissa Rouzer,
Graham Threadgill, Felix Montero
Use of Beckman Coulter’s Biomek FX to Automate Epitope Discovery for Specific Antigens
and Determine Optimal Peptides for Major Histocompatibility Complex (MHC) Class I Binding
Stimulation of T cell response to specific antigens is an emerging technique used in vaccine discovery. The
iTopia Epitope Discovery System from Beckman Coulter allows vaccine developers working on T cell mediated
vaccines to map and characterize binding of epitopes to MHC complexes. The iTopia System can identify antigenspecific
peptides that bind to any of eight different Class I MHC alleles, which represent approximately 90% of
the human population. iTopia System uses microtiter plates coated with MHC Class I monomers to which certain
peptides will bind in the presence of beta 2 microglobulin. Correctly folded complexes will be identified by binding
of a fluorescent antibody, which recognizes only the properly folded tertiary complexes. iTopia System analyzes
the binding, affinity and off-rates for the possible peptide/allele combinations of a selected protein. This speeds
vaccine development by allowing a systematic ranking of candidate epitopes for subsequent functional studies.
Automation of the liquid handling using the Biomek FX and data reduction are crucial to simplifying the iTopia
process. A manual method was devised to carry out the screening. However, for an antigen of 120 kilodaltons,
assuming screening 9-mer peptides, 992 peptides would need to be evaluated. It is estimated that 92 plates
for each allele would be required to complete the iTopia process. Automation of iTopia will make it easier for
companies working in vaccine discovery and development to incorporate this process into their workflow and to
increase the efficiency and accuracy of this technology.
4:00 pm Wednesday, February 4 Proteomics – Technology 1 Room B1
Nenad Gajovic-Eichelmann
Fraunhofer Institute Biomedical Engineering
Arthur-Scheunert-Allee 114-116
Bergholz-Rehbruecke, 14558 Germany
nenad.gajovic@ibmt.fhg.de
Co-Author(s)
Eva Ehrentreich-Foerster
Peter M. Schmidt
Joerg Henkel
Frank F. Bier
Active Arrays – Time Resolved Analysis in Microarrays for Binding Kinetics and Enzymatic
Activities
The primary task of a microarray experiment is to detect a lot of binding events simultaneously. Most applications
are transcription profiling and use fluorescence as label. Prior to the experiment, the sample has to be labeled by
a suitable fluorochrome. The binding is done in a separate incubation step, the final result is taken after drying.
Therefore usually microarray reader produce information on the fluorescence intensity at a given time of the
binding process. Progress towards diagnostic applications is still slow, quantitation of the results is a problem
and fabrication methods up to now are not reliable enough to allow for larg series production. The fluorescence
intensity measured in microarray experiments represents the amount of bound analyte that depends on the
concentration in the sample as well as on the affinity of the involved binding partners and time given for the
binding. It is not possible to differentiate these influencing factors in the usual setup. To overcome the limitations in
microarray technology developments are under way to facilitate measurement of binding kinetics in the microarray
format. Homogeneous sample flow over the whole microarray is one of the technological problems that recently
has been solved in our laboratory. Enzymatic reactions on immobilized substrates may also be observed using a
flow through type of scanning device. Parallel detection and comparison of a variety of substrates or templates are
now accessible in one single experiment and will be presented here. To demonstrate the power of the approach,
we chose a restriction endonucleases.