Biology of microbes
Philip A. Geis in Cosmetic Microbiology, 2006
The definition of Gram-positive and Gram-negative cell walls relates to two concepts: the color of the cell after the Gram stain and the physiological structure of the wall. Christian Gram developed a technique that allowed some bacteria to stain pink and others purple. When Gram devised the method, he did not know the reason for the staining. As a result of this differential staining, microbiologists began calling purple-stained bacteria “positive” and pink-stained bacteria “negative.” Later on, they found out that the purple-staining Gram-positive bacteria usually had thicker peptidoglycan layers and the pink-staining Gram-negative bacteria had thinner peptidoglycan layers. We will explore additional differences between Gram-positive and Gram-negative bacteria next.
The Identification of Cell Types in the Normal Adult Colon
Leonard H. Augenlicht in Cell and Molecular Biology of Colon Cancer, 2019
The structure of goblet cells directly reflects their secretory function. The cells are highly polarized and compartmentalized, with regular arrays of rough endoplasmic reticulum (RER) peripheral and subjacent to the nucleus within the basal cytoplasm, a well developed supranuclear Golgi complex, and an apical accumulation of mucin packed secretory granules (Figures 4 to 6). In most regions of the gastrointestinal tract, the goblet cell nuclei and cytoplasm stain intensely basophilic at the light level (Figure 4) and electron dense ultra-structurally (Figure 6). We have observed, however, that structurally comparable cells in the human proximal (Figure 5) and distal colon frequently have a pale nucleus and cytoplasm. The functional basis for this differential staining and electron density is unknown.
Histochemical Study of Estrogen Receptors in the Rat Uterus With a Hydrophilic Fluorescent Estradiol Conjugate
Louis P. Pertschuk, Sin Hang Lee in Localization of Putative Steroid Receptors, 2019
The principle of the fluorescent steroid histochemical techniques is based on the assumption that steroid hormone molecules are capable of binding to their receptors, soluble or insoluble, even when the hormone is covalently coupled to a dye or a carrier as long as its physiologically active determinants or radicals are exposed. Such a possibility was initially demonstrated with fluoresceinated 6-carboxymethyl oxime estradiol-170.40 However, because of its low solubility and hydrophobic nature that often cause poor differential staining in tissue sections, this compound has not been widely tested.
Antiproliferative Effect of Trifolium Pratens L. Extract in Human Breast Cancer Cells
Published in Nutrition and Cancer, 2019
Mozafar Khazaei, Mona Pazhouhi
Apoptosis was evaluated by detection of DNA fragmentation using an In Situ Cell Death Detection Kit, AP (Roche Diagnostics; Germany) and according to the manufacturer’s instructions. Briefly, after 48 h treatment with T. pratense extract in a 96 well plate, the cells were fixed using 4% paraformaldehyde in PBS (freshly prepared) for 1 h, permeabilized using a solution (0.1% Triton X-100, 0.1% sodium citrate) for 5 min on ice, and incubated with 50 μl of TUNEL mixture solution (label and enzyme solution) at 37 °C for 1 h in a humidified incubator. For differential staining of the cells the PI staining solution was added and the plate was incubated for 4 min at room temperature. Finally, cells were analyzed using a fluorescence microscope. All the mentioned stages are performed in dark condition. The apoptotic index of the cells was calculated as follow:
Innate inflammatory response to acute inhalation exposure of riot control agent oleoresin capsicum in female rats: An interplay between neutrophil mobilization and inflammatory markers
Published in Experimental Lung Research, 2020
Pompy Patowary, Manash Pratim Pathak, Kamaruz Zaman, Sanjai Kumar Dwivedi, Pronobesh Chattopadhyay
After 1, 3 and 24 h of OC exposure, rats were euthanized and BALF was collected from the left lung lobe by lavage through a tracheal cannula with cold phosphate-buffered saline (PBS) and lavages were performed with volumes of 5 mL per lavage. The retrieved fluid was kept on ice until centrifuged at 4 °C, 10,000 x g for 10 min in a cooling centrifuge (5430 R, Eppendorf AG, Hamburg, Germany). The resulting supernatant was aliquoted and stored at −80 °C for protein analysis and cytokine assay. Total leucocyte count was done manually in a Neubauer cell counting chamber (Paul Marienfeld GmbH, Bad Mergentheim, Germany). Hundred µL of resuspended cells were cytospun within 1 h onto glass slides using a filter card and cytocentrifuge cytospin centrifuge (Medilabsolutions, Haryana, India) (300 x g, 3 min). Cell differential viz. eosinophil, monocytes, and lymphocytes were assessed and counted following staining of cytocentrifuged preparations by differential staining microscopy with Diff-Quick (Hemacolor; Merck, Darmstadt, Germany) using standard morphological criteria and observed under a light microscope (Carl Zeiss, Gottingen, Germany). Cell counts were derived from at least 500 cell counts and are presented as the percentage of each cell type from the total number of cells.
Induction of different cellular arrest and molecular responses in low EGFR expressing A549 and high EGFR expressing A431 tumor cells treated with various doses of 177Lu-Nimotuzumab
Published in International Journal of Radiation Biology, 2020
ShishuKant Suman, Rashmi Priya, Mythili Kameswaran
Viability assay determines the percentage viability of cells based on the differential staining of two DNA-binding dyes. Nuclear dye stains nucleated cells while viability dye stains only the dying cells. Viability assay was carried out as per the procedure in the Guava ViaCount assay kit, Guava Technologies, Millipore, Darmstadt, Germany. Briefly, 50 μL of A431 and A549 (∼0.5 × 105) cells, both untreated and cells treated with 3.7 MBq, 18.5 MBq, and 37 MBq of 177Lu-Nimotuzumab,were mixed with 450 μL of Guava ViaCount reagent and incubated at room temperature (RT) in dark for 5 min. Sample acquisition and data analysis were performed using the ViaCount software module in the Guava EasyCyte Flow cytometer.
Related Knowledge Centers
- Bacteria
- Crystal Violet
- Peptidoglycan
- White Blood Cell
- Blood
- Staining
- White Blood Cell Differential
- Gram Stain
- Gram-Positive Bacteria
- Gram-Negative Bacteria