Panning technique

The first culture technique, reported in 1927, to be attempted commercially was a surface-culture, shallow-pan technique, though this method has not been used for many years. Relatively soon after this, in 1933, production using a submerged culture technique was reported and this method has been in use continuously since then. Various significant developments have been made, notably the addition of caldum carbonate to neutralise the adds produced in order to increase yields (1937) and the use of sodium hydroxide for neutralisation (1952). 

Other gene products or vaccine antigens may require an enrichment step. For example, many genes expressed on the cell surface, that is, receptors, adhesion molecules, and so on have been cloned by panning techniques where the cells... 

Washing experiments have been conducted on a pilot-scale rayon washing line that employs the rain-pan technique of gravity-flow wetting. In this system, precision-drilled, stainless-steel pans are used to "rain" measured quantities of solutions onto a batt of cotton. The batt is conveyed by a perforated stainless-... 

Dyer, P. A., Brown, P., and Edward, R. (1998) Immunomethods magnetic, column and panning techniques, in Cell Separation A Practical Approach (Fisher, D., Francis, G. E., and Rickwood, D., eds.), Oxford University Press, Oxford, p. 191. 

Koch, R, Kaempgen, E., Schuler, G. and Romani, N. (1992). Effective enrichment of murine epidermal Langerhans cells by a modified (mismatched) panning technique. J. Invest. Dermatol. 99, 803-807. 

DSC can be used to determine mixed edible fat. This can be illustrated with the results obtained from a study of a mixture of lard and beef fat using DSC and the sealed sample pan technique. 

The Linkam DSC is of the single specimen design and is described in detail elsewhere [36]. The cell comprises a silver enclosure around a thermocouple plate, the plate has a 3 X 0.5 mm slot and the sample is held in contact with the plate by a low thermal mass spring. A reference (cdibration) sample of the same thermal mass was first subjected to the temperature ramp and the thermal response of the neutral system recorded. The sample was then run and its thermal response recorded. The differential response was subsequently calculated from the electronic recordings, the single pan technique relies on the accuracy and reproducibility of the temperature control system and is comparable to that of a conventional, two-pan, heat-flux DSC (for example a Du Pont 990) [1]. 

Separation Techniques. Current methods for separating fatty acids are by solvent crystaUi2ation or by the hydrophili2ation process. Other methods that have been used in the past, or perhaps could be used in the future, are panning and pressing, solvent extraction, supercritical fluid extraction, the use of metal salts in assisting in separation, separations using urea complexes, and adsorption/desorption. 

HONO the mean flux was an emission of 1 ng Nm s but this includes periods both of emission and deposition. On several occasions, no concentration gradients were detected. The direction of the flux was dependent on NOj concentration, with emission observed only when NOj concentration was less than 10 ppb. The process of HONO exchange appears to be regulated by the net result of small deposition flux to the surface and a surface chemistry production of HONO from NOj. Fluxes of PAN deposition were measured using a chamber technique " and were small (less than 0.5ng Nm s ). 

These instruments, sometimes referred to also as sediment accumulation devices, weight the sediment as it accumulates on a weigh-pan at the base of the sedimentation column. The methods are cumulative ones. With the development of sensitive electro balances, the cumulative sedimentation technique is generally easier to perform and more accurate than is the incremental technique. The powder may be dispersed initially in the bulk of the fluid or added instantaneously at the top. An advantage of this type of equipment is the absence of the conical base, needed in sediment extraction devices, upon the walls of which some sediment may adhere. The danger of particles sticking to the vertical walls is however still present... 

Identification of dyes on dyed textiles is traditionally carried out by destructive techniques [493], TLC is an outstanding technique for identification of extracted dyestuffs and examination of inks. Figure 4.9 shows HPTLC/SERRS analysis of acridine orange [492], Wright et al. [494] have described a simple and rapid TLC-videodensitometric method for in situ quantification of lower halogenated subsidiary colours (LHSC) in multiple dye samples. The results obtained by this method were compared with those obtained by an indirect TLC-spectrophotometric method and those from HPLC. The total time for the TLC-videodensitometric assay of five standards and four samples applied to each plate was less than 45 min. The method is applicable for use in routine batch-certification analysis. Loger et al. [495,496] have chromatographed 19 basic dyes for PAN fibres on alumina on thin-layer with ethanol-water (5 2) and another 11 dyes on silica gel G with pyridine-water... 

Fluidized beds, in general, and the air-suspension technique patented by Wurster, in particular, now offer an attractive alternative to pan coating. The basic principle underlying their operation is to suspend the... 

The heat flow into (endothermic) or out (exothermic) of a sample as a function of temperature and time is measured using the technique of DSC. In particular, it is used to study and determine the temperature of thermal transitions. For polymers, these include Tg, the glass transition temperature, Tc, the (exothermic) temperature of crystallisation for polymers that can crystallise, and Tm, the (endothermic) melting temperature. A DSC measurement requires only a small amount of sample 2-20 mg of a film, powder, fibre or liquid samples can be analysed in a DSC pan. 

Pan CC, Chen PC, Tsay SH, et al. Cytoplasmic immunoreactivity for thyroid transcription factor-1 in hepatocellular carcinoma a comparative immunohistochemical analysis of four commercial antibodies using a tissue array technique. Am. J. Clin. Pathol. 2004 121 343-349. 

When heated, many solids evolve a gas. For example, most carbonates lose carbon dioxide when heated. Because there is a mass loss, it is possible to determine the extent of the reaction by following the mass of the sample. The technique of thermogravimetric analysis involves heating the sample in a pan surrounded by a furnace. The sample pan is suspended from a microbalance so its mass can be monitored continuously as the temperature is raised (usually as a linear function of time). A recorder provides a graph showing the mass as a function of temperature. From the mass loss, it is often possible to establish the stoichiometry of the reaction. Because the extent of the reaction can be followed, kinetic analysis of the data can be performed. Because mass is the property measured, TGA is useful for... 

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