Micro-injection

In contrast, a similar injection of the neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) produced a zone of total 5-HT denervation at least 2 to 3 mm in diameter. These chronic intracerebral micro injection experiments lend further support to the view that the parent compound is not itself neurotoxic (Berger 1989 Berger et al., in preparation Molliver et al. 1986). 

Mitler, M. M. Dement, W. C. (1974). Cataplectic-like behavior in cats after micro-injections of carbachol in pontine reticular formation. Brain Res. 68, 335-43. 

An important aspect of this enhancement strategy is its compatibility with current fabrication techniques, in particular polymer processing technology. The technique of micro-injection moulding was employed to produce polystyrene chips with an integrated array of cone structures intended for use in an aqueous environment. 

It may be useful to introduce impermeant fluorocromes without micro-injection. Permeabilization is suitable for small to medium cells. Large cells (e.g., Chara ) can be permeabilized osmotically (46) and become permeable to the fluorescent analogue of ATP, e-ATP (46). Vacuolar compartmentation still occurs, but the cell wall is porous to molecules of only 4158 Dalton (approx 4.8 nm). Internal fluorescence concentration increases only slowly because of the large volume of cytoplasm. 

Recently, the telecommunication industry has undergone rapid expansion, and a strong consumer trend towards smaller and lighter telecommunication devices, such as cellular phones and notebook computers, is indicated. Small connection sockets and chip carriers are micro-injection-molded parts requiring the high flowability, high mechanical properties and dimensional stability of LCPs. These merits are now thought to be another application field for LCPs in the electronics industry. 

Wash micro injection syringe fix injector leakage... 

Another general disadvantage of this approach relates to the use of the micro-injection technique to introduce the desired gene into the pronucleus of the fertilized egg. This approach... 

Transgenic pig. rabbit, and sheep by micro injection of foreign DNA iiitu egg nuclei. 

Figure 11.2 Subcellular distribution of fluorescein-labeled DNA fragments and plasmid DNA following microinjection into the cytoplasm. Double stranded circular plasmid DNA (3 kb and 6 kb) and DNA fragments (20,100,250 and 1 kb) were covalently labeled with fluorescein and microinjected into the cytoplasm of adherent HeLa cells as described in Lukacs et al., 2000. Following micro injection, cells were either fixed or incubated for 45 minutes at 37 °C and the distribution of DNA was visualized by fluorescence microscopy, (see Color Plate 10)...

Thombum, A.M. and Alberts, A.S. (1993) Efficient expression of miniprep plasmid DNA after needle micro-injection into somatic cells. Biotechniques, 14, 356-358. 

Color Plate 10 Subcellular distribution of fluorescein-labeled DNA fragments and plasmid DNA following micro injection into the cytoplasm, (see page 215)... 

Micro-injections in micro-flow and nano-flow systems are done with injectors in which the external sample loop is replaced with the internal fixed volume within the injector body. HPLC-on-a-chip systems also build the column into the injector body. The internal path within the injector body is abladed with a laser, packed with micro-packing material, and this serves as the separating media. The injector inlet is connected to the pumping system and the outlet to the detector. Sample is loaded into an internal loop in the load position, then injected onto the chip HPLC by turning the injector. Obviously, in a system like this sample size is very limited and the detector is usually a highly sensitive mass spectrometer. 

The special issue of micro injection molding applied for polymer heat exchangers will not be considered here. Additionally, for MEMS-like systems discussed above, other techniques, mostly based on etching, e.g. deep reactive ion etching (DR1E), are applied [20, 71, 86]. These techniques allow for future mass production of the small-scale (sub-watt fuel processors) devices to which they are applied. 

A 7] The fiber-coupled spectrometer is actually designed for applications with hand-held devices. A combination of micro injection molding and an electroforming process allows the production of a high-performance but low-cost device. The optical grating is, for example, replicated in plastic to reduce costs. 

A 8] The micro injection system relies on an electromagnetic drive and injects a small volume of only 0.5 pi per injection. The valve section is heated. The injected gas pulse is separated in a thin-layer separation column. 

Fig. 2.15. Schematic automated isocratic and gradient elution nemo-liquid chromatograph/ capillary electrochromatograph according Alexander et al. (reproduced from Ref. [44] with permission of the publisher). 1, high-voltage power supply (negative polarity) 2, platinum electrode 3, outlet reservoir vial 4, UV detector with on-column flow cell 5, nanocolumn 6, two-position switching valve 7, jack stand 8, fused-silica make-up adapter (split device) 9, ground cable 10, internal loop micro-injection valve 11, plexiglas compartment 12, autosampler 13, dynamic mixer 14, micro-LC pumps.

Fig. 2.16. Schematic of the coupling of the nanocolumn to the injection valve [44], 1, nano-column (75 pm I.D. x 360 pm O.D.) 2, knurled nut and ferrules 3, fused-silica make-up adapter (split device 504 pm I.D.) 4, micro-injection valve (column port 250 pm i.d.) 5, rotor 6, outlet port of the make-up adapter.

Micro-injection. Foreign DNA can be injected directly into the nucleus using a fine micropipette this is commonly used in fertilised animal egg cells. 

The first device integrated a microstructured multichannel plate fabricated by micro-injection molding from a two-component liquid silicon rubber material (Silopren LSR 4070) with an appropriately interfaced and temperature-controlled housing, as shown in Figure 3.1a. 

McDonough, J.H., McLeod, C.G., Nipwoda, M.T. (1987). Direct micro-injection of soman or VX into the amygdala produces repetitive limbic convulsions and neuropathology. Brain Res. 435 123-37. 

The direct caging of peptides and proteins has been achieved by many different groups [7], but rarely at the single cell level in a live organism [46]. These caged proteins have residual activity when caged, incomplete recovery of activity after uncaging, and most importantly, they must be micro-injected into the cells. 

Irvine, RF. and Moor, RM. (1986). Micro-injection of inositol 1,3,4,5-tetrakis-phosphate activates sea urchin eggs by a mechanism dependent on external Ca. Biochem. J. 240, 917-920. 

Tsou K, Jang CS (1964) Studies on the site of analgesic action of morphine by intracerebral micro-injection. Sci Sin 13 1099-1109... 

The quality of the DNA used for micro-injection is one of the most important determinants of success in transgenic experiments. Thus, it is essential that the DNA for micro-injection is absolutely free from aU contaminants that are toxic to the embryo, including traces of agarose, phenol, or ethanol. 

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