Integrated Coulter counter based on 2-dimensional liquid aperture control
نویسندگان
چکیده
In this paper, we present an integrated Coulter counter that applies a liquid aperture. The Coulter aperture is defined by a non-coaxial sheath of a conductive sample liquid that is surrounded on three sides by a non-conductive sheath liquid. The main advantage of this approach is that it prevents channel blocking, since the channel’s physical dimensions can be much larger than the Coulter aperture. Furthermore, the dimensions of the aperture can be dynamically adapted to the size of the particle by changing the flow-rates of the sample liquid and the sheath liquid. Both the sample and the sheath liquid are aqueous to prevent unstable flow conditions due to surface tension effects at the interface of the sheath liquid and the sample liquid. Diffusion of ions from the sample liquid into the sheath liquid is limited as long as a minimum flow-rate of 0.5 l/s is used. The maximum flow-rate is determined by the occurrence of instable flow behaviour at flow-rates higher than 10 l/s. The device can be made in a simple process requiring only four lithographic steps. Measurement results show that a high sensitivity can be obtained in a channel with relatively large physical dimensions. © 2003 Elsevier B.V. All rights reserved.
منابع مشابه
Electrohydrodynamic Coulter Counting
ABSTRACT A new paradigm of Coulter counting is developed using electrohydrodynamic liquid jets in lieu of solid state pores as the sensing aperture. The electrohydrodynamic jet was successfully used to detect micron-sized particles through resistive pulse sensing. Similar to conventional Coulter counting, the relative current change is proportional to the particle-tojet volume ratio. Compared t...
متن کاملAutomatic platelet counting with the Couler particle counter.
A method for accurately counting platelets is described using the Coulter counter model B fitted with a standard 100mu aperture tube. This enables the counter to be used for red and white cell as well as platelet counts using the same aperture tube. The method uses standard equipment except for a small inexpensive electronic speed controller.
متن کاملTwo-dimensional acoustic particle focusing enables sheathless chip Coulter counter with planar electrode configuration.
The field of cytometry has grown in scope and importance ever since the early 20th century with leaps in technology introducing the Coulter counter and the flow cytometer. Cytometry methods have brought about a revolution for the medical and biotechnology industry by providing fast and accurate analysis of cell and particle suspensions. Recent developments in the field aim at improving current ...
متن کاملContinuous Recording of Cell Number in Logarithmic and Synchronized Cultures.
An instrument for the continuous recording of cell number has been developed and is being used to record changes in populations of logarithmic and synchronized cultures of protozoan flagellates. A Coulter cell counter is used in conjunction with a counting chamber that is fitted with a flexible polyethylene aperture (75 micro in diameter). This aperture rarely becomes blocked and appears to be ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2004