Optimization of DNA-directed immobilization on mixed oligo(ethylene glycol) monolayers for immunodetection.
Anal Biochem
; 423(1): 26-35, 2012 Apr 01.
Article
in En
| MEDLINE
| ID: mdl-22285698
ABSTRACT
The development of protein chips has suffered from problems regarding long-term protein stability and activity. We present a protein sensor surface for immunodetection that is prepared by a DNA-directed protein immobilization method on a mixed self-assembled monolayer (SAM). By this approach, an immobilized single-stranded DNA (ssDNA) surface can be transferred/modified into a protein chip by flowing in ssDNA-conjugated protein when the protein chip measurement is needed. Therefore, the long-term stability of the protein chip will not be a problem for various applications. We tried various compositions for the SAM layer, the length of the ssDNA spacer, the end-point nucleotide composition, and the processes of ssDNA immobilization of the SAM for an optimized condition for shifting the DNA chip to a protein chip. The evaluations were made by using surface plasmon resonance. Our results indicated that a 501 ratio of oligo(ethylene glycol) (OEG)/COOH-terminated OEG and DNA sequences with 20mer are the best conditions found here for making a protein chip via a DNA-directed immobilization (DDI) method. The designed end-point nucleotide composition contains a few guanines or cytosines, and ssDNA immobilization of the SAM by dehybridizing immobilized double-stranded DNA (dsDNA) can improve the hybridization efficiency.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
DNA, Single-Stranded
/
Immunoassay
/
Proteins
/
Ethylene Glycol
/
Surface Plasmon Resonance
Language:
En
Journal:
Anal Biochem
Year:
2012
Document type:
Article
Affiliation country:
Taiwan