Colorimetric detection of polynucleotides on polypropylene slices.
The gold-label-silver-stain method (GLSS) for DNA hybridization detection has been receiving increased interest as a colorimetric detective method, demonstrating the advantages of non-radioactivity, non-quenching effect of fluorescence and simplicity for analytical equipment. A colorimetric detection based on the GLSS method was applied to DNA arrays in situ synthesized on polypropylene (PP) slices. In this paper a simple plasma treatment was employed to graft amino (-NH2) on the polypropylene slice surfaces, where DNA probes were immobilized via in situ synthesis. Hybridization was accomplished by a sandwich hybridization format. With the amplification of Silver Enhancer Solution, the hybridization signals were recorded with a scanner. A target DNA concentration as low as 100 fM was detected. Complementary and mismatched sequences were clearly distinguished, and the ratio of the background-subtracted gray scale values for a perfect match, single-base mismatch, 2-base mismatch and 3-base mismatch is 22:16:9:4. The sensitivity of the in situ synthesis system was 3 orders of magnitude higher than that of the spotting system, and the signals of the former were about 2-times stronger than that of the latter under the same target DNA concentration.
Nie
Libo
L
Key Laboratory of Molecular and Biomolecular Electronics, Southeast University, Ministry of Education, Nanjing 210096, China.
Tang
Jianxin
J
Guo
Huishi
H
Chen
Hong
H
Xiao
Pengfeng
P
He
Nongyue
N
D003124:Colorimetry; D004247:DNA / Q000737:chemistry; D015342:DNA Probes; D006046:Gold / Q000737:chemistry; D017403:In Situ Hybridization; D007202:Indicators and Reagents; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D009206:Myocardium / Q000648:ultrastructure; D009841:Oligonucleotides / Q000032:analysis; D011119:Polynucleotides / Q000032:analysis*; D011126:Polypropylenes / Q000032:analysis*; D012834:Silver / Q000737:chemistry
D015342:DNA Probes; D007202:Indicators and Reagents; D009841:Oligonucleotides; D011119:Polynucleotides; D011126:Polypropylenes; D012834:Silver; D006046:Gold; D004247:DNA