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Biomedical subjects

B A Burdick

Publications and source records attributed to B A Burdick.

5 recordsLinked to original sources
PubMed1986

A multilayer element for determining hemoglobin in whole blood: principles and analytical performance.

We described the structure and analytical performance of a thin-film element for determining total hemoglobin in whole blood. The element can be used with the Kodak Ektachem DT60 analyzer. The method, analogous to the standard Drabkin's method, provides accurate and precise results on 10-microL samples of undiluted whole blood. Dynamic range is linear from 0 to 200 g/L, and the method is relatively free from interference.

Autoanalysis↗
PubMed1978

Multilayer film elements for clinical analysis: applications to representative chemical determinations.

Using the general concept of a dry multilayer analytical element, we can change chemical procedures and configurations to assay several blood components. In the assay of serum urea nitrogen, urease in the reagent layer catalyzes the hydrolysis of urea. A semipermeable membrane excludes aqueous base, but allows ammonia to diffuse to an underlying indicator layer. For the amylase determination, the enzyme hydrolyzes a dyed-starch substrate coated on top of the spreading layer; this produces small fragments, which diffuse to a registration layer. The increase of absorbance at 540 nm is correlated with amylase activity. Bilirubin complexes with a cationic polymer at the interface between the spreading and reagent layers. The direct reading at 460 nm allows determination of total bilirubin in the range 1 to 500 mg/liter. Tirglycerides are hydrolyzed in the spreading layer, and the resulting soluble glycerol readily diffuses into the reagent layer, where it is phosphorylated and subsequently oxidized by glycerophosphate oxidase to yield dihydroxyacetone phosphate and hydrogen peroxide. Peroxidase catalyzes production of a color commensurate with the hydrogen peroxide produced.

Amylases↗
PubMedDate not supplied

Polymeric thiols as enzyme activators of serum creatine phosphokinase.

Several hydrophilic polymeric thiols were prepared from amino-activated polymeric supports by reaction with N-acetylhomocystein ethiolactone. Supports include agaroses, cellulose, Glycophase controlled-pore glass, and Matrex acrylic beads. Thiol content in these polymers was 3-72 mumol SH/g dry polymer. Several were effective solid-phase activators of the sulfhydryl-dependent enzyme creatine phosphokinase at concentrations comparable to that of monomeric thiol required for enzyme activation. The kinetic activation curves for the polymeric and the monomeric (thioglucose) activators were similar, suggesting unhindered interaction of the enzyme with the polymeric activator.

3-Mercaptopropionic Acid↗