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Biomedical subjects

L Hanks

Publications and source records attributed to L Hanks.

3 recordsLinked to original sources

Assembly of high-resolution restriction maps based on multiple complete digests of a redundant set of overlapping clones.

An approach to restriction-site mapping and contig building that uses fragment-size data from multiple complete digests of a set of clones that oversample a genomic region is presented. Maps containing both fragment-length data and clone-end data are maintained for each restriction enzyme. Synchronization between the maps for the different enzymes is achieved by requiring the clone-end maps for all enzymes to be compatible. Basic concepts that underlie multiple-complete-digest mapping--including the match/merge approach to map incorporation, extension vs assimilation, ambiguity, and clone-end compatibility--are presented. An initial application of multiple-complete-digest mapping to real data on a set of cosmid clones suggests that this mapping method has exceptional power to produce accurate maps that are well suited to the needs of large-scale DNA-sequencing projects.

Algorithms↗

Fragment collapsing and splitting while assembling high-resolution restriction maps.

In the process of constructing high-resolution restriction maps via greedy algorithms, a classical anomaly, known as fragment collapsing, introduces errors into the maps that impedes further map assembly. Fragment collapsing occurs when two different genomic fragments of approximately the same length and occurring in the digestion of two different overlapping clones are incorrectly identified as representative of a single genomic fragment. This introduces a single fragment of commensurate length into an incorrect position in the map. The present work describes techniques for detecting and correcting such anomalies.

Algorithms↗

Gas chromatographic method for determining strychnine residues in alfalfa.

A gas-liquid chromatographic procedure is described for determining strychnine in alfalfa with a nitrogen-phosphorus detector. Alfalfa samples containing strychnine residues are chopped and extracted in a blender using ethyl acetate, sodium carbonate, and sodium sulfate, and the organic extract is extracted with 0.1N H2SO4 solution, made basic, and subsequently extracted with methylene chloride. Following concentration, the strychnine residues are quantitated by peak height, using an external standard. Recoveries for 0.05 ppm spikes were 88 +/- 11%.

Chromatography, Gas↗