Infrared fluorescent detection of D1S80 alleles

Portable plastic syringe as a self-actuated pump for long-distance uniform delivery of liquid inside a microchannel and its application for flow-through polymerase chain reaction on chip

A strategy for realizing self-actuated pumping with uniform flow rate over a long distance is introduced using hands-on operation of disposable syringe, and was applied for on-chip flow-through PCR inside a serpentine PMMA microchannel.

Development of a passive micromixer based on repeated fluid twisting and flattening, and its application to DNA purification

We have developed a three-dimensional passive micromixer based on new mixing principles, fluid twisting and flattening. This micromixer is constructed by repeating two microchannel segments, a "main channel" and a "flattened channel", which are very different in size and are arranged perpendicularly. At the intersection of these segments the fluid inside the micromixer is twisted and then, in the flattened channel, the diffusion length is greatly reduced, achieving high mixing efficiency. Several types of micromixer were fabricated and the effect of microchannel geometry on mixing performance was evaluated. We also integrated this micromixer with a miniaturized DNA purification device, in which the concentration of the buffer solution could be rapidly changed, to perform DNA purification based on solid-phase extraction.

Infrared fluorescent automated detection of thirteen short tandem repeat polymorphisms and one gender-determining system of the CODIS core system

We used an infrared (IR) automated fluorescence monolaser sequencer for the analysis of 13 autosomal short tandem repeat (STR) systems (TPOX, D3S1358, FGA, CSF1PO, D5S818, D7S820, D8S1179, TH01, vWA, D13S317, D16S359, D18S51, D21S11) and the X-Y homologous gene amelogenin system. These two systems represent the core of the combined DNA index systems (CODIS). Four independent multiplex reactions, based on the polymerase chain reaction (PCR) technique and on the direct labeling of the forward primer of every primer pair, with a new molecule (IRDye800), were set up, permitting the exact characterization of the alleles by comparison with ladders of specific sequenced alleles. This is the first report of the whole analysis of the STRs of the CODIS core using an IR automated DNA sequencer. The protocol was used to solve paternity/maternity tests and for population studies. The electrophoretic system also proved useful for the correct typing of those loci differing in size by only 2 bp. A sensibility study demonstrated that the test can detect an average of 10 pg of undegraded human DNA. We also performed a preliminary study analyzing some forensic samples and mixed stains, which suggested the usefulness of using this analytical system for human identification as well as for forensic purposes.

Multiplex amplification of STR loci with gender alleles using infrared fluorescence detection

The analysis of short tandem repeat (STR) polymorphisms has proven extremely useful for gene mapping, paternity testing, and forensic analysis. Several commercial products are currently available for performing amplification and analysis of STRs. We have adapted Promega Geneprint Systems for use with a high sensitivity infrared (IR) fluorescent automated DNA sequencer. IR-labeled amplification products are generated by including a small quantity of IR-labeled dATP in the reaction. Several Geneprint STR loci can be multiplexed together with the amelogenin sex identification locus in a single amplification reaction. We have successfully amplified up to five Geneprint STR loci together with the amelogenin locus thus improving the throughput of analysis. Purified genomic DNA as well as simulated forensic samples have been utilized for these multiplex amplifications.