Cell handle

Auroux et al. give an up-to-date description of the application of pTAS components and systems, including cell culture and cell handling, immunoassays, DNA separation and analysis, polymerase chain reactions, and sequencing [43] (see also [44] for a description of the pTAS components and systems). 

Selected entries from Methods in Enzymology [vol, page(s)] Association constant determination, 259, 444-445 buoyant mass determination, 259, 432-433, 438, 441, 443, 444 cell handling, 259, 436-437 centerpiece selection, 259, 433-434, 436 centrifuge operation, 259, 437-438 concentration distribution, 259, 431 equilibration time, estimation, 259, 438-439 molecular weight calculation, 259, 431-432, 444 nonlinear least-squares analysis of primary data, 259, 449-451 oligomerization state of proteins [determination, 259, 439-441, 443 heterogeneous association, 259, 447-448 reversibility of association, 259, 445-447] optical systems, 259, 434-435 protein denaturants, 259, 439-440 retroviral protease, analysis, 241, 123-124 sample preparation, 259, 435-436 second virial coefficient [determination, 259, 443, 448-449 nonideality contribution, 259, 448-449] sensitivity, 259, 427 stoichiometry of reaction, determination, 259, 444-445 terms and symbols, 259, 429-431 thermodynamic parameter determination, 259, 427, 443-444, 449-451. 

The vast majority of facilities maintain their cells manually, with several technicians working diligently in front of biological safety cabinets. Even with the best planning, this becomes difficult to scale when some cell-handling steps must occur over the weekend. Some facilities have turned to automation to maintain their standard cell lines taking some of the routine burden off skilled technicians and effectively achieving 24/7 operation when fully functional. 

For the last ten years or so, a handful of groups world-wide have been working to develop microtools for cell handling. The aim is to develop a series of basic elements which can be juxtaposed and connected to build useful devices. This work draws heavily on techniques pioneered for semiconductor manufacture. The results are promising and the number of groups is increasing as the result of industrial interest. 

Microstructure based biotechnology is a fascinating field of research which is beginning to produce its first applications. It is not a simple down-scaling of existing techniques but an attempt to find new cell handling methods and to create new interfaces between living material and inanimate objects. 

The first practical applications are likely to include field cages for cell positioning, inexpensive cell sorters and single cell cultivation depots. But once the basic elements for cell handling have been developed, very many kinds of device will become easy to produce. We can expect to see new systems for use in medical diagnosis and pharmaceutical testing within the next decade and a range of cell based biosensors. 

Simons, K. and E. Ikonen (2000). How cells handle cholesterol. Science 290 1721-1726. 

The platinum wire of the other electrode is plated with a cadmium deposit by immersing the electrode in a beaker containing a 0.1 M solution of CdS04 and a pure cadmium rod. The electrode is connected to the negative terminal of a 1.5-V dry cell, and the cadmium rod is connected to the positive terminal. Current is passed through this plating bath until a heavy deposit of cadmium is visible on the electrode. This cadmium electrode is then transferred to the cell. Handle the electrode with care to avoid flaking off any of the cadmium deposit. It is advisable to keep the electrode wet at aU times. 

Regardless of the strategy, it is imperative to understand the mechanism(s) involved in the delivery process. Targeting of DNA to a specific cell population by any method can only be optimized when the components of the delivery system are fully characterized. This will ultimately enable researchers to effectively assess the efficiency of DNA delivery and cellular uptake, critical parameters in gene transfection. It is important to determine how cells handle exogenously administered DNA and to determine where the rate-limiting step is in the transfection process. This chapter will address many of the current issues related to the development and analysis of nonviral-mediated DNA delivery methods, with emphasis on the lipid-based carrier systems. 

It has been known for 20 years that secretion of granule bound materials generally requires the presence of calcium in the medium (9). If calcium is omitted from the fluid perfusing a secretory tissue, evoked secretion is abolished or at least diminished. However, not all secretory cells handle calcium in the same way and more recent work emphasizes the role of calcium in membrane stabilization, the influence of magnesium ion on calcium mediated events, and the effect of stimulation frequency on calcium metabolism. 

During stressful situadons, some cells in the body convert glycogen to glucose. What effect does this conversion have on cellular osmotic balance Explain how cells handle this situation. 

MICROFLUIDICS AS AN ENABLING TECHNOLOGY FROM CLASSICAL LIQUID HANDLING TO SINGLE-CELL HANDLING... 

We have identified four important biological application areas for magnetic particle handling in microfluidic systems cell handling and separation, nucleic acid processing and detection, immunoassays, and catalysis. We showed that specific magnetic labeling permits to select or deplete certain... 

Care should be taken in cell handling prior to the lysis step, as the presence of nonintact cells increases the background of nonspecific protein crosslinking. The bifimctional reagent solution should be prepared freshly. 

Simons K, Ikonen E (2000) How cells handle cholesterol Science 290 1721-1726 Skaper SD (2008) The biology of neurotrophins, signalling pathways, and functional peptide mimetics of neurotrophins and their receptors. CNS Neurol Disord Drug Targets 7 46-62 Strauss KI, Narayan RK, Raghupathi R (2004) Common patterns of bcl-2 family gene expression in two traumatic brain injury models. Neurotox Res 6 333-342 Sun D, Newman TA, Perry VH, Weller RO (2004) Cytokine-induced enhancement of autoimmune inflammation in the brain and spinal cord implications for multiple sclerosis. Neuropathol Appl Neurobiol 30 374-384... 

McClain et al. [6] demonstrated a simple microchip that integrated cell handling, rapid cell lysis, and electrophoretic separation and detection of fluorescent cytosolic dyes. Cells flowed through a field-free channel under a hydrodynamic force until they entered a chaimel region that introduced both alternating-current (AC) and direct-current (DC) electric fields plus an inflow of detergent (Fig. 2). Cells were lysed and their contents were steered into a separation channel immediately. The analysis throughput up to 15 cells per minute was achieved with continuous flow of cells. 

Jaeger MS, Mueller T, Schnelle T (2007) Thermometry in dielectrophoresis chips for contact-fi-ee cell handling. J Phys D 40 95-105... 

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