Cho EJ, Collett JR, Szafranska AE, Ellington AD. Optimization of aptamer microarray technology for multiple protein targets.
Anal Chim Acta 2006;
564:82-90. [PMID:
17723365 DOI:
10.1016/j.aca.2005.12.038]
[Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2005] [Revised: 12/08/2005] [Accepted: 12/12/2005] [Indexed: 10/25/2022]
Abstract
Aptamer-based microarrays for the quantitation of multiple protein analytes have been developed. A multiplex aptamer microarray was generated by printing two RNA aptamers (anti-lysozyme and anti-ricin) and two DNA aptamers (anti-IgE and anti-thrombin) on to either streptavidin (SA) or neutravidin (NA)-coated glass slides. However, substantial optimization was required in order to ensure the simultaneous function of the aptamer:analyte pairs. The effects of protein labeling, assay buffer, surface coating, and immobilization chemistry and orientation were investigated. A single buffer (PBS buffer containing 5 mM MgCl2 and 0.1% Tween 20) was found to work well with all the aptamers, even though this was not the buffer originally used in their selection, while neutravidin-coated slides yielded a lower detection limit, wider detection range, and more uniform background than streptavidin-coated slides. Incubation with Cy3-labeled proteins yielded sensitive, target-specific, and dose-dependent responses to each protein. Target protein concentrations as low as 72 pg/mL (5 pM, lysozyme), 15 ng/mL (0.5 nM, ricin), 1.9 ng/mL (0.01 nM, IgE), and 170 ng/mL (5 nM, thrombin) could be detected. These results show that aptamer arrays can potentially be used with numerous proteins in parallel, furthering the notion that aptamer arrays may be useful in proteomics.
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