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T M Olefirowicz

Publications and source records attributed to T M Olefirowicz.

4 recordsLinked to original sources
PubMed1990

Capillary electrophoresis in 2 and 5 microns diameter capillaries: application to cytoplasmic analysis.

Capillary electrophoresis with electrochemical detection in 2- and 5-micron capillaries has been developed to study ultrasmall biological environments. Sample volumes as low as 270 fL have been injected into the electrophoresis capillary with subattomole detection limits for easily oxidized species. We have applied this method to the analysis of single cell cytoplasm. Sampling of the cytoplasm is accomplished by inserting one end of the electrophoresis capillary directly into a single nerve cell. The high-voltage end of the electrophoresis capillary has been etched with hydrofluoric acid to form a microinjector. This injection scheme represents an improvement over those previously used for similar applications. The excellent selectivity of this method is demonstrated for catecholamine and indolamine neurotransmitters and their metabolites found in the invertebrate system, the pond snail Planorbis corneus.

Animals↗
PubMed1990

Capillary electrophoresis with indirect amperometric detection.

The use of indirect amperometric detection with capillary electrophoresis is demonstrated. The system consists of a porous glass coupler which allows amperometric detection at a carbon fiber electrode placed in the end of the capillary. 3,4-Dihydroxybenzylamine is added to the buffer system as a continuously eluting electrophore. Indirect amperometric detection in 9-mumol I.D. capillaries provides detection limits as low as 380 attomole for the amino acid arginine. Finally, both direct and indirect amperometric detection can be accomplished simultaneously.

Amino Acids↗
PubMed1990

Dopamine concentration in the cytoplasmic compartment of single neurons determined by capillary electrophoresis.

It has long been a goal of the biochemist to study the chemistry of single cells. This is particularly important in neuroscience, since each cell can maintain a specific function and identity. Investigations into neurotransmitter compartmentalization within the cell body of neurons should lead to an understanding of the role of the cell body in metabolism, uptake and storage of neurotransmitters. Using capillary electrophoresis, it has been possible to separate and detect attomole levels of neurotransmitter in picoliter volumes of cytoplasm withdrawn from single neurons of the pond snail, Planorbis corneus. This work demonstrates, for the first time, the direct determination of the cytoplasmic concentration of dopamine in single, intact neurons.

Cytoplasm↗