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Biomedical subjects

S L Pentoney

Publications and source records attributed to S L Pentoney.

5 recordsLinked to original sources
PubMed1995

Biopolymer synthesis on polypropylene supports: oligonucleotide arrays.

High-density oligonucleotide arrays have been constructed on clear, aminated polypropylene film using conventional phosphoramidite-based synthesis chemistries. A semiautomated 64-channel fluidic chemical delivery system is used to prepare the 64 x 64 array containing 4096 oligonucleotide elements. The completed array has been successfully used in the hybridization and fluorescence (Streptavidin-FITC) detection of a biotinylated 18-mer oligonucleotide target complementary to the F508 codon region of the cystic fibrosis transmembrane conductance regulator gene. A hybridization simulation model based upon Nearest Neighbor approximations is used to predict the outcome of the array hybridization experiment.

Base Sequence↗
PubMed1994

Characterization of digoxigenin-labeled B-phycoerythrin by capillary electrophoresis with laser-induced fluorescence. Application to homogeneous digoxin immunoassay.

A laser-induced fluorescence (LIF) immunoassay technique based on capillary electrophoretic (CE) separation is demonstrated. The analysis of digoxin in serum at clinically useful concentration levels of 10(-9) to 10(-10) M is achieved using this technique. The chemistry presented here using digoxigenin-labeled B-phycoerythrin was selected as a convenient model for the exploration of CE-LIF-based immunoassays. The LIF system described here exhibits detection limits in the low 10(-11) M range for several common fluorophores. The data presented in this report are one of the first examples of nanomolar quantitative analysis in a human serum matrix by CE.

Binding, Competitive↗
PubMed1992

A single-fluor approach to DNA sequence determination using high performance capillary electrophoresis.

The Tabor and Richardson strategy for enzymatic chain termination sequencing of DNA using relative peak intensity has been adapted to high performance capillary gel electrophoresis with laser induced fluorescence detection. This approach to DNA sequencing involves the use of only a single fluor and results in significant reduction in the time required to determine a DNA sequence without the use of highly complicated and expensive instrumentation. We present a modification of the Tabor and Richardson approach employing two reactions, each containing complementary mixtures of only three ddNTP's in the concentration ratio 4:2:1. The DNA sequence is determined by relative peak height and by assigning the missing ddNTP to "gaps" between the peaks. The use of only three terminators/reaction simplifies the software task of differentiating between the termination types and makes more efficient use of the available dynamic range. Both complementary mixes generate complete sequence information and the two data files are combined in order to make a more confident sequence call. This process helps to eliminate errors caused by occasional non-uniform incorporation of ddNTP's or false terminations and also alleviates some of the difficulty associated with reading through compressed regions of the electropherogram.

Base Sequence↗
PubMedDate not supplied

Contribution of secondary structure to DNA mobility in capillary gels.

Intramolecular base pairing at the 3' end of single-stranded DNA molecules can cause increased electrophoretic mobility. In DNA sequencing separations this can result in compressions, where multiple oligomers differing in length by one base comigrate, which complicate sequence analysis. Using a novel approach to the application of capillary electrophoresis to DNA sequencing, incorporation of formamide into capillary gels, different separation field strengths, and external heating of the capillary are examined for their ability to resolve compressions. The identity of the 3' terminal nucleotide has also been observed to influence oligomer mobility in cross-linked acrylamide slab gels. We utilize automated data collection from DNA sequencing separations to show that a similar effect is also present in linear acrylamide capillary gels run at high field strengths. We also demonstrate the ability of capillary electrophoresis to separate synthetic oligos of the same length but differing in composition by one base, or of the same base composition but different sequence.

Base Sequence↗