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Biomedical subjects

A Brunsting

Publications and source records attributed to A Brunsting.

6 recordsLinked to original sources
PubMed1982

Is the central dogma of flow cytometry true: that fluorescence intensity is proportional to cellular dye content?

Measurements and theoretical calculations of fluorescent emission from four samples of polystyrene microspheres (diameter 0.92, 1.63, 1.90 and 4.18 microns) containing the same fluorescent dye show a general dependence upon particle size, emission angle, and polarization conditions. However, for the excitation and detection conditions used in flow cytometry, the relative fluorescent intensities measured for the four particle sizes are proportional to the dye content to +10% accuracy, independent of particle size. Accordingly, the central dogma of flow cytometry 'that fluorescence is proportional to cellular dye content' is valid to this accuracy for these solid, highly refractive polymer particles. Most mammalian cells are much less refractive, therefore, should conform more closely to the central dogma.

Animals↗
PubMed1975

Light scattering from nucleated biological cells.

The light scattered from nucleated biological cells has been investigated by using four different theoretical models: an opaque disk, a homogeneous sphere, an opaque ring, and a coated sphere. By comparing these four models, diffraction at the edges of the cell and the nucleus has been found to be the predominate scattering mechanism for nucleated biological cells at low angles. The scattering patterns of nucleated cells are found to have a fine lobe (high-frequency) structure dependent on whole cell size, and an envelope lobe (low-frequency) structure dependent on relative nucleus size. The models indicate that the present technique for measuring cell size with a single low-angle light detector is highly dependent on the nucleus to cell diameter ratio. Whole cell size is better estimated by the ratio of the outputs from two low-angle detectors.

Cell Nucleus↗
PubMed1974

Differential light scattering from spherical mammalian cells.

The differential scattered light intensity patterns of spherical mammalian cells were measured with a new photometer which uses high-speed film as the light detector. The scattering objects, interphase and mitotic Chinese hamster ovary cells and HeLa cells, were modeled as (a) a coated sphere, accounting for nucleus and cytoplasm, and (b) a homogeneous sphere when no cellular nucleus was present. The refractive indices and size distribution of the cells were measured for an accurate comparison of the theoretical model with the light-scattering measurements. The light scattered beyond the forward direction is found to contain information about internal cellular morphology, provided the size distribution of the cells is not too broad.

Cell Division↗