DUAL-CHANNEL LASER PLATELET AGGREGATION ANALYZER/COUNTER
* Covered by Russia, U.S. and other foreign patents
Aggregation Analyzers produced by Biola Ltd. are designed to study aggregation of the platelets or other cells, to determine concentration of the cells in a suspension, and to assess their shape.
Aggregation is measured both by routine turbidimetric technique and by recently developed method based on real-time measurement of aggregate mean size. The turbidimetric metric of Born and O'Brien is most widely used in modern studies of platelet aggregation. It is based on recording of the changes in optical density in platelet-rich plasma. This approach makes it possible to study not only aggregation, but also the changes in platelet shape. The latter is particular important, because the changes in platelet shape can mask the initial stage of aggregation. In addition, formation of microaggregates (consisting of less than 100 platelets) may not be reflected by the changes of optical transmission in a suspension.
In 1989, Z. A. Gabbasov et al. introduced a new method to study platelet aggregation - the optical density fluctuation analysis (ODFA), which is based on analysis of optical transmission caused by stochastic changes in the number of particles in the optical channel. The relative value of these fluctuations is proportional to aggregate mean size. This parameter is used to study aggregation kinetics. Extremely high sensitivity of ODFA makes it ideal to study spontaneous aggregation and the aggregation induced by low concentration of inductors. It is also used to study aggregation of subcellular particles and macromolecules.
The development of ODFA made it possible to measure concentration of particles in stirred suspension. Aggregation Analyzers are supplied with original software developed for IBM-compatible computers run under Windows. The software displays aggregation curves and parameters in real time, stores the data with timing marks and commentary records on the hard disk, and provides the software tools to examine and process the data off-line.
SPECIFICATION:Sample volume 0.3 mL.
Two independent channels and 4 preincubation wells per channel.
Light source - semiconductor laser, wavelength 0.86 mm.
Thermostat - 25 to 42+0.2oC or OFF independently for each channel.
Stirring speed - 100 to 1200 RPM independently for each channel.
Automatic setup of 0% and 100% light transmission.
Built-in microcontroller with menu-driven user interface.
16 position alpha-numeric display.
Interface to PC - USB.
AC line requirements - 220 to 240V, 50 or 60 Hz.
Dimensions, mm - 300x300x85.
Weight, kg - 2.8 kg.
Counter: (models 230LA, 230LA-2):
- concentration range (human platelets) 50...500 thousands/mL
- systematic error <5%
- reproducibility (standard deviation ) <5%
- Born G.V.R. Quantitative investigation into the aggregation of blood platelets. J. Physiol. (Lond), 1962, p.67P-68P.
- O'Brien J.R. Platelet aggregation. Part II. Some results of a new study. J. Clin. Pathol., 1962, 15, p.452-455.
- Latimer P., Born G.V.R., Michal F. Application of light-scattering theory to optical effects associated with morphology of blood platelets. Arch. Biochem. Biophys., 1977, 180, p. 151-159.
- Kitek A. and Breddin K. Optical density variations and microscopic observations in the evaluation of platelet shape change and microaggregate formation. Thromb. Res., 1980, 44, p.154-158.
- Thompson N.T., Scrutton M.C. and Wallis R.B. Particle volume changes associated with light transmittance changes in the platelet aggregometer: dependence upon aggregating agent and effectiveness of stimulus. Thromb. Res., 1986, 41, p.615-626.
- Latimer P. and Wamble F. Light scattering by aggregates of large colloidal particles. Applied Optics, 1982, 21, p.2447-2455..
- Gabbasov Z.A., Popov E.G., Gavrilov I.Yu. and Posin E.Ya. Platelet aggregation: the use of optical density fluctuations to study microaggregate formation in platelet suspension. Thromb.Res., 1989, 54(3), p.215-223.
- Gabbasov Z.A., Popov E.G., Gavrilov I.Yu., Posin E.Ya. and Markosyan R.A. A new high-sensitive method for platelet aggregation analysis. Laboratornoye delo, 1989, 2 10, p.15-18.
- Gabbasov Z.A., Popov E.G., Gavrilov I.Yu., Posin E.Ya. and Markosyan R.A. A new methodical approach to research of platelet aggregation in vitro., BEBM, 1989, 2 10, p. 437-439.
- Tertov V.V., Sobenin I.A., Gabbasov Z.A., Popov E.G. and Orechov A.N. Lipoprotein aggregation as an essential condition of intracellular lipid accumulation caused by modified low density lipoproteins, BBRC, 1989, 163(1), p.489-494.
- Gabbasov Z.A., Gavrilov I.Yu. and Popov E.G. The use of optical density fluctuations for determination of platelet concentration in stirred suspention. Platelets, 1992, 2, p.281-282 .
|Aggr Software version 4.|
File date: 20.10.2014. File size: 6882 kB.