Quantification of microRNA by gold nanoparticle probes.

MicroRNAs are important posttranscriptional regulators of gene expression in animals and plants. A sensitive and specific detection method is urgently needed for intensive studies on differential expression and regulatory roles of microRNA. Here we present a simple and reliable method for the quantification of microRNA.

Ultrasensitive densitometry detection of cytokines with nanoparticle-modified aptamers.

Background: Aptamers mimic properties of antibodies and sometimes turn out to be even better than antibodies as reagents for assays. We describe the establishment of an ultrasensitive densitometry method for cytokine detection by nanoparticle (NP)-modified aptamers.

Methods: The assay simultaneously uses a gold NP-modified aptamer and a biotin-modified aptamer to bind to the target protein, forming a sandwich complex.

Ultra-sensitive colorimetric method to quantitate hundreds of polynucleotide molecules by gold nanoparticles with silver enhancement.

An ultra-sensitive colorimetric method to quantitate hundreds of polynucleotide molecules by gold nanoparticles with silver enhancement has been developed. The hybridization products from the target polynucleotides with biotin-labeled probes and gold nanoparticle-functioned oligonucleotides were immobilized to microplates via avidin-biotin system, and the absorbance signals of gold nanoparticles were amplified by silver enhance solution. This sandwich colorimetric assay can detect as few as 600 molecules for single-strand oligonucleotides and as few as 6000 molecules for double-strand polynucleotides in a 50 microL reaction system.

[Cohort mortality study of dust exposed miners in iron mine].

Objective: To investigate the main diseases jeopardizing the health of the iron miners and to explore the relationship between dust exposure and malignancies as well as other diseases.

Methods: A retrospective study with a cohort of 7,469 workers employed between January 1, 1972 and December 31, 1974 in Daye Iron Ore Mine Co. in Hubei Province was conducted.