COULTER ELECTRONICS

P. W. HeUeman, The Coulter Electronic Particle Counter. Aspects and Views in Counting and Si ng oJErythroytes,D>Qi Bilt HoUand, the Netherlands, 1972, Chapt. 7-11. 

FIGURE 1 Effect of (sequential) extrusion of MLV dispersions through polycarbonate membrane filters (Unipore) with pore sizes of 1.0, 0.6, 0.4, 0.2, and 0.1 ym on the mean liposome diameter. DXR-containing MLV (phosphatidylcholine/phosphatidylserine/ cholesterol 10 1 4) mean diameter of nonextruded dispersion about 2 ym pH 4. Mean particle size determined by dynamic Light scattering (Nanosizer, Coulter Electronics). (From Crommelin and Storm, 1987.)... 

Critical Flocculation Electrolyte Concentration The critical flocculation electrolyte (Na2S0.) concentration was determined by following the average particle size of the dilute dispersion (where the particles were coated with PVA corresponding to the plateau adsorption) as a function of Na2S0 concentration, using a Coulters Nanosizer (Coulters Electronics Ltd) as described before (20). 

Electrical zone sensing counters such as the Coulter counter (Coulter Electronics, Hialeah, Fla.) and the Elzone (Particle Data, Inc., Elmhurst, 111.) can analyze particles in the range of about 1200 to 0.4 /am. To cover this range,... 

Anonymous, Coulter Counter—Industrial Bibliography, Coulter Electronics Ltd., Bedfordshire, England, May 1986. 

This method has been approved as an ASTM procedure (F316). The typical apparatus used is schematically illustrated in Figure 3.11. An instrument based on this method has been introduced by Coulter Electronics recently (Venkataraman et al. 1988). 

The suspensions are centrifuged and washed twice in 3% FBS/PBS. They are again centrifuged and washed twice in 3% FBS in PBS with 0.1% Triton X-100. The pellets are resuspended and incubated with 0.5 ml of 1% FBS containing propidium iodide (10 pg/ml Calbiochem, San Diego, CA) and RNAse (1 mg/ml) in Hank s balanced salt solution (without phenol red) for 30 min at 37°C. The samples are analyzed on a Coulter Electronics XL-MCL or a Becton Dickinson FACScan flow cytometer with standard argon ion laser excitation and filter configuration for the FTTC/propidium iodide dye combination. 

Narrowly classified latices are available from Dow Chemicals [134] but doubt has been expressed on the accuracy of their sizing. A 3.49 pm polystyrene latex was independently sized by electron microscopy and found to have a mean diameter of 3.40 pm [135]. This standard was used by Coulter Electronics as a standard to size other Dow latices [136] that are available from them as standard suspensions. 

Coulter Counter and other scientific instruments. Industrial Bibliography January 1992, Coulter Electronics Ltd., Northwell Drive, Luton, Beds LU3 3RH, England, 450... 

Coulter counter (model Zb, Coulter Electronics Inc., Hialea, FL) ... 

Information on the Coulter Counter is available from Coulter Electronics, Inc., 590 West 20th St., Hialeah, FL 33010. 

Oja, T. Bott, S. Sugrue, S. Doppler electrophoretic light scattering analysis using the coulter DELSA 440. Coulter Electronics Luton, 1989. 

Cell and Spore Number Determination, The number of cells or spores were determined by the following standard methods at various times after inoculation PetroflF-Hausser counting method with a phase contrast microscopy (Carl Zeiss) and the Coulter counting method (Coulter Counter, Model B, Coulter Electronics Corp.). No cellular chains were observed. 

FITC-conjugated monoclonal antibody (MAb) against an intracellular viral antigen. In the case of HIV-1 a specific anti-p24 MAb, KC57, is available from Coulter Electronics Ltd. (UK). 

Coulter N4 + MD Submicron Particle Size Analyzer (Coulter Electronics, Miami, Florida). 

The mean ( SD) diameter of CSIL is 200 35 nm, that of IgG-L is 210 13.1 (Coulter N4 MD Submicron Particle Size Analyzer, Coulter Electronics, Miami, Florida). 

This method has been approved as a ASTM procedure [120-122] and used in the commercial computer controlled Coulter Porometer (Coulter Electronic Ltd) for pore sizes much larger than 0.44 pm. However the theoretical basis used for the evaluation of the accumulated data neglects the specificity of gas flow in pores and incorrectly considers the flowing gas as an incompressible fluid. The assumption of gas flow dependency only on AP distorts the resulting... 

Fig. 14.13 Scheme of the DACOS analyser. The rotary light source is located under the central cover. Around it spin at 0.6 rps eight interference filters for measurements at eight different wavelengths. (Courtesy of Coulter Electronics). 

The use of scanning electron microscopy (SEM) is not as satisfactory. Other methods of measuring particle size are somewhat indirect and actually derive their calibration from electron microscopy. In effect, measurements with instruments such as a Coulter Electronics Multisizer or a disc centrifuge average the diameters of a great many particles. In the case of the disc centrifuge, the... 

The BaS04 suspension was then titrated stepwise with polyelectrolyte and allowed to equilibrate for about 30 minutes after each addition. The zeta potential of the resulting suspension was then determined by Doppler electrophoretic light scattering analysis using a Coulter Electronics DELSA 440. BaS04 suspensions were titrated to a toti polyelectrolyte concentration of 100 mg polyelectrolyte/m BaS04. 

Coulter Electronics Limited Northwell Drive Luton LU3 3RH England... 

Total smface areas were measured by nitrogen adsorption at -196 C, using an automated instrument (Omnisorp lOOCX, Coulter Electronics Limited). The cross sectional area of the nitrogen molecule was assumed to be 16.2 x 10 m. Pore type and volume data were also obtained by this method, using t-plot analysis. Metal areas were measured by selective chemisorption of hydrogen at 30 °C in the same instrument. Copper surface areas were measured in a flow system by nitrous oxide chemisorption at 60 C. 

Coulter type instrumentation available from Coulter Electronics Ltd., is listed in Table 19.2 (Multisizer and Model 2M) and Appendix 1. 

Coulter Electronics Ltd., supplies a range of laser particle size distribution apparatus (LSlOO and LS130) (see Table 19.2 and Appendix 1). 

Surface area measurement Thermo Electron Shimadzu Varian Instruments Thass Beckman Coulter Electronics Ltd. 

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