The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

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Initial sequencing and analysis of the human genome.

http://image.sciencenet.cn/olddata/kexue.com.cn/blog/admin/images/upfiles/2007101622257911935.pdf

The growing impact of click chemistry on drug discovery.

Small-molecule fluorescent probes embody an essential facet of chemical biology. Although numerous compounds are known, the ensemble of fluorescent probes is based on a modest collection of modular “core” dyes. The elaboration of these dyes with diverse chemical moieties is enabling the precise interrogation of biochemical and biological systems. The importance of fluorescence-based technologies in chemical biology elicits a necessity to understand the major classes of small-molecule fluorophores. Here, we examine the chemical and photophysical properties of oft-used fluorophores and highlight classic and contemporary examples in which utility has been built upon these scaffolds.

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Bright Ideas for Chemical Biology

Demand for DNA sequence information has never been greater, yet current Sanger technology is too costly, time consuming, and labor intensive to meet this ongoing demand. Applications span numerous research interests, including sequence variation studies, comparative genomics and evolution, forensics, and diagnostic and applied therapeutics. Several emerging technologies show promise of delivering next-generation solutions for fast and affordable genome sequencing. In this review article, the DNA polymerase-dependent strategies of Sanger sequencing, single nucleotide addition, and cyclic reversible termination are discussed to highlight recent advances and potential challenges these technologies face in their development for ultrafast DNA sequencing.

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Emerging technologies in DNA sequencing

This review presents a robust strategy to design photosensitizers (PSs) for various species. Photodynamic therapy (PDT) is a photochemical-based treatment approach that involves the use of light combined with a light-activated chemical, referred to as a PS. Attractively, PDT is one of the alternatives to conventional cancer treatment due to its noninvasive nature, high cure rates, and low side effects. PSs play an important factor in photoinduced reactive oxygen species (ROS) generation. Although the concept of photosensitizer-based photodynamic therapy has been widely adopted for clinical trials and bioimaging, until now, to our surprise, there has been no relevant review article on rational designs of organic PSs for PDT. Furthermore, most of published review articles in PDT focused on nanomaterials and nanotechnology based on traditional PSs. Therefore, this review aimed at reporting recent strategies to develop innovative organic photosensitizers for enhanced photodynamic therapy, with each example described in detail instead of providing only a general overview, as is typically done in previous reviews of PDT, to provide intuitive, vivid, and specific insights to the readers.

Recent Strategies to Develop Innovative Photosensitizers for Enhanced Photodynamic Therapy.

We have synthesized a set of four energy transfer dyes and demonstrated their use in automated DNA sequencing. The donor dyes are the 5- or 6-carboxy isomers of 4'-aminomethylfluorescein and the acceptor dyes are a novel set of four 4,7-dichloro-substituted rhodamine dyes which have narrower emission spectra than the standard, unsubstituted rhodamines. A rigid amino acid linker, 4-aminomethylbenzoic acid, was used to separate the dyes. The brightness of each dye in an automated sequencing instrument equipped with a dual line argon ion laser (488 and 514 nm excitation) was 2-2.5 times greater than the standard dye-primers with a 2 times reduction in multicomponent noise. The overall improvement in signal-to-noise was 4- to 5-fold. The utility of the new dye set was demonstrated by sequencing of a BAC DNA with an 80 kb insert. Measurement of the extinction coefficients and the relative quantum yields of the dichlororhodamine components of the energy transfer dyes showed their values were reduced by 20-25% compared with the dichlororhodamine dyes alone.

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New energy transfer dyes for DNA sequencing

Fluorescent dye phosphoramidite labelling of oligonucleotides

The invention provides compositions electron-deficient nitrogen heterocycle-substituted fluorescein dyes and methods in which the dyes are conjugated to substrates and used as detection labels in molecular biology experiments. The electron-deficient nitrogen heterocycles include pyridine, quinoline, pyrazine, and the like. Substrates include polynucleotides, nucleosides, nucleotides, peptides, proteins, carbohydrates, and ligands.

Electron-deficient nitrogen heterocycle-substituted fluorescein dyes

Dibenzorhodamine compounds having structure (1) are disclosed, including nitrogen- and aryl-substituted forms thereof. In addition, intermediates useful for synthesizing such compounds are disclosed, such intermediates having structure formula (I). In formula (I), R1 is H or (a) wherein Y is H, lower alkyl, lower alkene, lower alkyne, aromatic, phenyl, polycyclic aromatic, heterocycle, water-solubilizing group, or linking group, including substituted forms thereof. When R1 is H, the C-12-bonded nitrogen and the C-12 and C-13 carbons form a first ring structure having from 4 to 7 members, and/or the C-12-bonded nitrogen and the C-11 and C-12 carbons form a second ring structure having from 5 to 7 members. The compounds of formula (I) further include aryl- and nitrogen-substituted forms thereof. The invention further includes energy transfer dyes comprising the dibenzorhodamine compounds, nucleosides labeled with the dibenzorhodamine compounds, and nucleic acid analysis methods employing the dibenzorhodamine compounds.

Dibenzorhodamine dyes useful as fluorescent labelling agents

The present disclosure provides reagents that can be used to label synthetic oligonucleotides with rhodamine dyes or dye networks that contain rhodamine dyes.

Krishna G. Upadhya

Papers

New energy transfer dyes for DNA sequencing

Fluorescent dye phosphoramidite labelling of oligonucleotides

Electron-deficient nitrogen heterocycle-substituted fluorescein dyes

Dibenzorhodamine dyes useful as fluorescent labelling agents

Reagents useful for synthesizing rhodamine-labeled oligonucleotides