Concluding Remarks
Proteomics research is increasingly turning towards gel-free approaches such as protein microarrays as well as other techniques including tandem MS (LC-MS/MS) for quantitative as well as functional analysis. Protein microarrays allow for HT analysis of immobilized proteins, with whole-proteome assays being their ultimate goal. Abundance-based protein arrays, in the form of capture arrays or reverse-phase protein blots, have found extensive applications in immunological studies, diagnosis and monitoring of diseases like cancer, and interactions of proteins with peptides, small molecules and other biomolecules. Efforts to minimize nonspecific interactions and cross-reactivity have helped in improving the specificity of these arrays. Functional protein arrays have witnessed a slow transition from cell-based techniques to cell-free expression systems for the generation of microarrays. Cell-free technologies have adeptly overcome the hurdles posed by protracted cell-based methods such as expression in heterologous hosts, purification and need for storage, and have facilitated the parallel synthesis of several proteins on demand in a single reaction. Cell-free-based protein microarrays have been used for numerous applications, including biomarker discovery, vaccine development, immunological studies and protein interaction analysis.
Detection systems for protein microarrays have strived to achieve real-time, multiplexed detection of proteins and their interactions. Despite continuous advancements and increasing applications of label-based strategies, the focus has been shifting towards label-free approaches that achieve detection of target molecules by examining an inherent property of the query molecule itself, including mass, dielectric property, light scattering and refractive index. They have been able to overcome several of the limitations posed by label-based approaches. Some of the emerging label-free techniques include SPRi-based systems, silicon nanowire field-effect transistors and carbon nanotubes and nanowires. These sensitive tools have been successfully applied to several proof-of-concept studies but their applicability to large, high-density microarrays is yet to be demonstrated. While protein microarrays and detection techniques have made rapid progress in past 5 years, further progress in detection techniques will provide enhanced sensitivity and specificity, and further miniaturized array formats.
Expert Rev Proteomics. 2011;8(1):61-79. © 2011 Expert Reviews Ltd.
Cite this: Protein Microarrays and Novel Detection Platforms - Medscape - Feb 01, 2011.
