coulter_counter

coulter_counter - Harvard-MIT Division of Health Sciences...

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Coulter Counter A Coulter counter is a device for counting individual cells. Cells are made to flow through a short, narrow channel while the resistance of the channel is measured. Because the cell blocks part of the channel, the resistance will increase while the cell is in the channel. This transient change can be used not only to count cells, but to estimate their size. The channel cross-sectional area needs to be small enough that the cell blocks a significant fraction of it. Moreover, the channel needs to be short for two reasons. First, so that the portion of the channel length blocked by the cell contributes significantly to the overall resistance. Second, so that only one cell is likely to be in the channel at a given time. Here we show two simple techniques for making a Coulter counter. The first technique uses an existing microchannel design. A plastic master is made from a portion of a microchannel, as shown in the image below. The center channel in this master has cross-sectional dimensions of 50x75 micrometers. Harvard-MIT Division of Health Sciences and Technology
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This note was uploaded on 01/24/2010 for the course HST. 410J / taught by Professor Alexanderaranyosi during the Spring '07 term at MIT.

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coulter_counter - Harvard-MIT Division of Health Sciences...

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