细胞技术

Based on morphological, biochemical, and molecular criteria two distinct modes of cell death can be recognized: necrosis and apoptosis (1–5). Necrosis generally results from enzymatic digestion of the cells and denaturation of its proteins as the response to gross injury. An early event of ...

Flow cytometry is a laser-based technology that is used to measure characteristics of biological particles. This technology is used to perform measurements on whole cells as well as prepared cellular constituents such as nuclei and organelles. Flow cytometers scan single particles or ...

Changes in steady-state mRNA levels may represent early molecular events in immune cells that can ultimately predict and define cellular function, activation, differentiation, and transformation (1). The ability to detect and accurately quantitate these changes in specific cel ...

Flow cytometric DNA content analysis of human neoplasia provides quantitative information on DNA ploidy, clonal DNA heterogeneity, and proliferative activity. These submicroscopic features are important for the biological and clinical evaluation of tumors as demonstrat ...

Acridine orange (AO) is the most notable member of the acridine fluorescent dye family. Because of its versatility and diverse biological applications, it has been widely used in basic and clinical research fields (1–10). For flow cytometric application, AO offers distinct advantages ov ...

Measurement of a DNA histogram can be achieved by fixing or permeabilizing cells and staining them with a DNA-binding dye, such as propidium iodide (PI). The histogram will yield the percentage of cells in the G1, S, and G2/M phases of the cell cycle (1). Although some inferences about the movement of cells t ...

Cell-cell electrofusion (CCE) is a process that involves forcing cells into close juxtaposition and then inducing fusion by delivering electric pulses to the cells. CCE has proven to have many practical applications. It has been used for monoclonal antibody (Mab) production (4,5), hybrid ...

Recent studies reported the so-called “electroinsertion” of proteins having a membrane-spanning sequence into mouse red blood cell or Chinese hamster ovary cell membrane by exposing the cell suspension to electrical field pulses (1–6). The viability of the pulsed cells is not affected. ...

The discovery that one drug transporter, P-glycoprotein, decreases intracellular concentrations of many anticancer drugs explains how drug resistance could simultaneously develop to structurally unrelated compounds (1). These discoveries have focused attention on the ...

Drug resistance is a subject that covers two areas. In one case it refers to the ability of microbes to defeat antibiotics. In a different setting it refers to the ability of cancer cells to resist chemotherapy. In the first case, the drug resistance is evaluated on the basis of the percentage of viable cells a ...

Inhaled particles can cause a spectrum of responses ranging from simple clearance to pathologic reactions, including acute injury and chronic fibrosis. In vivo and in vitro studies of particulate interaction with lung cells has greatly advanced our understanding of the mechanisms of p ...

Cell plasma membranes act as highly impermeable barriers for the exchange of molecules between cells and external medium. Transfer of compounds can only take place via the existence of specific transport systems that allow a limited number of molecules to cross membranes. Alteration in me ...

The first evidence of clonal growth and differentiation of hematopoietic cells was obtained by Bradley and Metcalf in 1966 (1) by using an agar semi solid culture system. These progenitor cells, initially called “Colony Forming Units in Culture” (CFU-C) developed into colonies after sever ...

Nearly all hematopoietic cells in mammals derive from precursors that undergo much or all of their development in the bone marrow. In vitro models for many lineages are available and represent modifications of the original bone marrow culture system designed by Dexter and Lajtha (1). In this ch ...

Eukaryotic microalgae and prokaryotic cyanobacteria (blue-green algae) have traditionally been maintained by serial subculture, with the frequency of transfer being largely determined by the growth characteristics of the strain. This technique has the dual disadvantages of ...

Chloroplast thylakoids are the site of photosynthetic light reactions, electron transport, adenosine triphosphate (ATP) synthesis and nicotinamide adenine dinucleotide phosphate (NADP) reduction in plant cells. Isolated thylakoids are therefore the necessary prere ...

Free-living amoebae (FLA) are unicellular, eukaryotic protozoa found in virtually all soil and aquatic environments (1). All FLA are characterized by a feeding and replicating trophozoite form that, in most genera, can produce a resistant cyst stage in response to adverse conditions (1). F ...

Many aspects of mycology today necessitate living cultures. Traditional taxonomy is being supplemented by molecular biological techniques often requiring growing organisms. The need to keep particular strains for confirmation of results, further studies, and as references is ...

Increased interest in biotechnology along with the requirement for strains associated with patent applications to be deposited in a reconized collection, under the terms of the Budapest Treaty (1977), has increased the demand for the maintenance of microorganisms in designated cul ...

Viruses are noncellular forms of life and are much smaller and less biochemically complex than the simplest unicellular organisms. They consist of either RNA or DNA as a single molecule, or in some cases as a segmented genome, enclosed by one or more proteins. These proteins protect the nucleic acid f ...