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Rapid flow of passive neutrophils into a 4 microns pipet and measurement of cytoplasmic viscosity.

Publication ,  Journal Article
Needham, D; Hochmuth, RM
Published in: Journal of biomechanical engineering
August 1990

Neutrophils from five different individuals are isolated with a density separation technique. A total of 151 unactivated (passive) cells are rapidly aspirated at constant suction pressure and at room temperature into a pipet with a diameter of 4 microns. The suction pressures in excess of an initial yield threshold are 0.5, 1 and 2 kPa and are comparable to those encountered in the microcirculation. These pressures are well in excess of the small suction pressure of approximately 20 Pa that is required to form a static hemispherical bump on the cell. At a given aspiration pressure, the leading edge of an individual cell is "tracked" as it flows into the pipet. A theory based on the flow of a Newtonian liquid from either a hemisphere or a spherical segment into a cylinder is used to model the entry process. Both theory and experiment show that during most of the entry process the leading edge of the cell moves at a nearly constant velocity with a rapid acceleration at the end. For cells from five different individuals at the three different excess aspiration pressures, Newtonian theory gives a cytoplasmic viscosity of 135 +/- 54 Pa.s and overall entry times of 3.3s (0.5 kPa), 1.6s (1 kPa) and 0.82s (2 kPa). These results and those of Evans and Yeung at lower aspiration pressures indicate that the complex cytoplasm inside unactivated neutrophils behaves as a nearly Newtonian fluid with a viscosity on the order of 10(2) Pa.s over almost a two order of magnitude range in aspiration pressure and, thus, rate of deformation.

Duke Scholars

Published In

Journal of biomechanical engineering

DOI

EISSN

1528-8951

ISSN

0148-0731

Publication Date

August 1990

Volume

112

Issue

3

Start / End Page

269 / 276

Related Subject Headings

  • Viscosity
  • Rheology
  • Reference Values
  • Neutrophils
  • In Vitro Techniques
  • Humans
  • Elasticity
  • Cytoplasm
  • Biomedical Engineering
  • 4003 Biomedical engineering
 

Citation

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Needham, D., & Hochmuth, R. M. (1990). Rapid flow of passive neutrophils into a 4 microns pipet and measurement of cytoplasmic viscosity. Journal of Biomechanical Engineering, 112(3), 269–276. https://doi.org/10.1115/1.2891184
Needham, D., and R. M. Hochmuth. “Rapid flow of passive neutrophils into a 4 microns pipet and measurement of cytoplasmic viscosity.Journal of Biomechanical Engineering 112, no. 3 (August 1990): 269–76. https://doi.org/10.1115/1.2891184.
Needham D, Hochmuth RM. Rapid flow of passive neutrophils into a 4 microns pipet and measurement of cytoplasmic viscosity. Journal of biomechanical engineering. 1990 Aug;112(3):269–76.
Needham, D., and R. M. Hochmuth. “Rapid flow of passive neutrophils into a 4 microns pipet and measurement of cytoplasmic viscosity.Journal of Biomechanical Engineering, vol. 112, no. 3, Aug. 1990, pp. 269–76. Epmc, doi:10.1115/1.2891184.
Needham D, Hochmuth RM. Rapid flow of passive neutrophils into a 4 microns pipet and measurement of cytoplasmic viscosity. Journal of biomechanical engineering. 1990 Aug;112(3):269–276.

Published In

Journal of biomechanical engineering

DOI

EISSN

1528-8951

ISSN

0148-0731

Publication Date

August 1990

Volume

112

Issue

3

Start / End Page

269 / 276

Related Subject Headings

  • Viscosity
  • Rheology
  • Reference Values
  • Neutrophils
  • In Vitro Techniques
  • Humans
  • Elasticity
  • Cytoplasm
  • Biomedical Engineering
  • 4003 Biomedical engineering