Biomedical subjects

E Kordwig

Publications and source records attributed to E Kordwig.

3 recordsLinked to original sources

PubMed1977

Uniform lateral orientation, caused by flow forces, of flat particles in flow-through systems.

Recently, it was shown that the lateral orientation of sperm cells disturbs the deoxyribonucleic acid distribution measured by fluorescence in a laterally laser-illuminated flow system. The present results show how flat particles may be influenced to assume a uniform lateral orientation. This was achieved by choosing the geometrical dimensions of the hydrodynamic focusing flow path. High speed photographs of fixed chicken erythrocytes oriented in experimental chambers are presented.

Animals↗

PubMed1977

Fluvo-metricell, a combined cell volume and cell fluorescence analyzer.

A new flow through instrument that simultaneously measures cell volume (resistance pulse technique) and cell fluorescence in the same orifice will be described. The fluorescence pulses of the hydrodynamically focussed cells are picked up by the optics via the axial direction (principle of Dittrich and Goehde, Z Naturforsch 24b:360, 1969). There is no coordination problem between the fluorescence and the resistance pulses to be observed because a new type of transducer is used. The electronic system provides gating of one or two parameter histograms. Function tests are performed with the incorporated two-parameter test spectrum generator. Different examples of using the instrument in practice are shown. The volume that may be measured with an orifice of 70 micron diameter ranges between 4 and 1400 micron3 (1:350). Coefficients of variation of the fluorescence below 2% are measured.

Cytological Techniques↗

PubMed1977

A volume-activated cell sorter.

A sorter that is activated by the resistance pulses of a Coulter orifice (volume detector) has been developed. The problem arising from the distortion of the volume signals produced by the electric droplet forming and charging voltages are avoided by special shielding and grounding of the volume detector. Experiments with beads and leukocytes are described. The maximal processing rate at this time is 2000 cells/sec, the purity of sorted fractions is better than 97%, and the viability of sorted cells is better than 80%.

Cell Separation↗