Protein Microarrays for Bioreactor Bioproduct Monitoring

Rotating wall vessels (RWV) are widely used for cell culture in simulated microgravity conditions. Sensor technologies capable of monitoring the expression of proteins on a large scale (proteomics) are needed to fully exploit the unique capabilities of RWVs. This Phase II effort is part of a program to develop an advanced analytical monitoring system for quantitative detection of bioreactor bioproducts in microgravity. The underlying technology is grating-coupled surface plasmon resonance, which permits sensitive, label-free, parallel detection of bioproducts in a complex fluid without purification steps in real time. The objective of this effort is to develop generic capture microarrays that will allow for the site-directed self-assembly of tailor-made, user-defined high-density multi-component assay chips. This is accomplished by immobilizing a library of short oligonucleotide PNA (peptide nucleic acid) probe molecules on a chip in a site-specific manner using covalent attachment chemistry and a spotting method. Capture molecules that will compose the array are tagged (off-line) with a library of complementary PNA sequences. Then, the microarray is assembled by flowing the complex mixture of different PNA-tagged compounds over the chip, which through hybridization reactions, form site-directed self-assembled arrays. A set of microarrays will be produced and a complementary set of protein-PNA conjugates relevant to microgravity research.