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DARTMOUTH MEDICAL SCHOOL DEPARTMENT OF PHYSIOLOGY Program in Molecular, Cellular and Systems Physiology

Cell Images

Optical Sections through a Neutrophil

Eight serial images obtained by using a confocal microscope to section optically through a peripheral blood neutrophil. The DNA in the nucleus was stained red with propidium iodide; the polymorphic shape of the nucleus identifies the cell as a neutrophil. The surface membranes of the cell are stained green with a monoclonal antibody for HLA Class II proteins, indicating that, after activation by cytokines, neutrophils are capable of reacting to super antigens like toxic shock protein. The cell was imaged on a Bio-Rad 1024 confocal laser scanning microscope by Neil Fanger, a Ph.D. student in the laboratory of Dr. Paul Guyre.

Breast Cancer Cells stained for Actin and Phosphotyrosine

Cells from the MCF-7 breast cancer line stained with rhodamine phalloidin to visualize F-actin filaments and with fluorescein anti-phosphotyrosine (showing tyrosine phosphorylated proteins on the ends of the actin filaments at the focal adhesions of the cells). The image was obtained on a Bio-Rad 1024 confocal microscope by Dr. Michael Fay, as part of a research project in the laboratory of Dr. William North aimed at examining the role of neuropeptides on cancer cell growth and cell migration/invasion.

Phase Contrast Image of a Cytotoxic Plaque formed by a Macrophage Fluorescence Image of a Cytotoxic Plaque formed by a Macrophage A phase contrast image of a macrophage (arrow) forming a plaque in a monolayer of ox erythrocytes. The macrophage is the cytotoxic effector cell and the erythrocytes are the target cells that leave empty plaques when they are killed by the macrophage. The size of the plaque in the erythrocyte layer is a measure of the cytotoxic ability of the macrophage. When growth medium is made fluorescent with fluorescein conjugated to high molecular weight dextran, plaques in a layer of ox erythrocytes can be quantitated by confocal fluorescence microscopy (see image on right). An image of the fluorescence observed when a macrophage in fluorescein-dextran medium forms a plaque in a monolayer of ox erythrocytes. In this image, the intense fluorescent area (orange) marks the plaque area that was observed in the bright field image (see image on left). The area of the plaque can be determined by software routines and this area can serve as a measure of the cytotoxic potential of the macrophage. Both these phase contrast and fluorescence images were obtained on a Meridian Ultima laser scanning confocal microscope in a project by Germo Gericke, Nicole Benoit, Ken Orndorff, Solveig Ericson, and Alice Givan (Department of Physiology and Englert Cell Analysis Laboratory) aimed at studying the recovery of macrophage function after bone marrow transplantation.

Localization of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)

Plasma membrane localization of the cystic fibrosis gene product, the cystic fibrosis transmembrane conductance regulator (CFTR), tagged with green fluorescent protein (GFP) in living human airway epithelial cells. Human airway epithelial cells from a cystic fibrosis patient were transfected with a GFP-CFTR expression vector. Laser scanning confocal fluorescence microscopy was used to image living cells. GFP-CFTR fluorescence, shown in green, is localized to the plasma membrane and filopodia. The image was obtained by Bryan Moyer, as part of his doctoral work in the laboratory of Dr. Bruce Stanton.

Actin Filaments in a Breast Cancer Cell

A cell from the MCF-7 breast cancer line stained with rhodamine phalloidin to visualize F-actin filaments. The image was obtained on a Bio-Rad 1024 confocal microscope by Dr. Michael Fay, as part of a research project in the laboratory of Dr. William North aimed at examining the role of neuropeptides on cancer cell growth and cell migration/invasion