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Biomedical subjects

T R Boyde

Publications and source records attributed to T R Boyde.

At least 19 recordsLinked to original sources
PubMed1993

Pulsed-field acceleration: the electrophoretic behavior of large spherical particles in agarose gels.

In agarose gel electrophoresis, periodically inverting or interrupting the applied field may greatly accelerate the migration of polystyrene microspheres, in a manner varying with pulse times, and the observed zones are made sharper. The particles concerned are just large enough that under constant field they appear not to enter the gel at all or to migrate very slowly: and merely lowering the applied field may also enhance their electrophoretic migration, though to a lesser extent than with field pulsing. These effects may be accounted for by gel mesh flexibility which, varying with the nature of the migrating species, may either help or hinder migration.

Electrophoresis, Agar Gel↗
PubMed1983

Aspartate aminotransferase isoenzymes--differential kinetic assay in serum.

The isoenzymes of aspartate transaminase differ in their kinetic properties in that the cytoplasmic isoenzyme is more readily inhibited by adipate and by 2-oxoglutarate (substrate) at low pH. A differential kinetic assay based on this phenomenon has been optimised for use in assays of serum samples. The new method agrees well with an immune absorption procedure. Methods based on chromatographic separation of the isoenzymes fail in the presence of serum.

Adolescent↗
PubMed1980

Improvements in the determination of urea using diacetyl monoxime; methods with and without deproteinisation.

A rapid and reproducible method is described for measurement of urea in biological materials (after deproteinisation) and in serum (without deproteinisation). Urea is colorimetrically determined with diacetyl monoxime and thiosemicarbazide in the presence of sulphuric acid, phosphoric acid and ferric chloride. The sensitivity of the colorimetric reaction and stability of the colour are enhanced over existing related procedures and the serum blank diminished, enabling urea to be precisely measured in micro amounts (1--5 microliters) of serum.

Chromogenic Compounds↗
PubMed1980

Preparative gel electrophoresis at high sample load. The effect of some experimental variable on separation performance.

The separation of model protein pairs (hemoglobin/albumin, trypsin/chymotrypsin, hemoglobin A/hemoglobin F) was studied in an apparatus for preparative gel electrophoresis at loads up to 40mg/cm2 of the cross-sectional area of the gel bed. Separation was favored by higher ionic strength and by longer migration path. Under the conditions used and within the load range studied, increasing total protein load had no adverse effect but increased voltage gradient, temperature, or gel strength were all unfavorable.

Adult↗
PubMed1978

Volume exclusion errors and the determination of serum zinc.

Volume exclusion gives rise to positive errors in the results of plasma or serum zinc determinations by methods in which protein is precipitated and the zinc extracted into solution. The error is amplified if two extraction steps are employed, and may be +20% or more. The same effects must be expected in any analysis involving comparable extraction procedures, whatever the substance being determined.

False Positive Reactions↗