Coulter counter
Date: 1961-1970
Inventory Number: 2003-1-0104b
Classification: Counter
Subject:
Maker: Coulter Electronics, Inc. (1958-present)
User: John B. Little
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
46.5 × 34.5 × 44 cm (18 5/16 × 13 9/16 × 17 5/16 in.)
DescriptionA black rectangular box with a black rubber handle on top. The apparatus features two long wires coming out of the side: a thin grey one, and a thicker black one which presumably is meant to connect to the Coulter Channelyzer (see 1999-1-0090a or 2003-1-0104a).
The front facade is divided into unequal thirds. The faceplate of the top third is black and features, in the top right corner, the Coulter Counter logo in the middle
of an outlined white rectangle. In the top left corner is a screen which is the same size as the outlined rectangle. Beneath the rectangular screen are two equal sized square screens; these monitors are green and grey and are labeled "Sizing" and "Debris" respectively. The second third is a large rectangular cavity covering the entire right side of the front of the apparatus, beginning below the logo and continuing down near the very bottom. In it, the user has access to the sample-mount apparatus. The final third of the front facade covers the lower left quadrant of the instrument and extends somewhat higher. On the metallic faceplate of this third are featured four dials: at the top, a small one for amplification (the range is from 1/8 to 64, with an "Off" setting); in the middle, two large ones for determining the threshold (the left for the lower threshold and the right for the upper threshold, with both ranging from -10 to 110); and near the bottom, another small one for the aperture current (ranging from 8 to 1/18, with an "off" setting). On the left hand side on a black strip at the very bottom is a power button meant to be pulled "on".
In a long embedded oval near the top of left side of the box is a series of four dials. Presumably these allow the user to adjust the settings for the screen(s). In a smaller embedded oval near the middle of the left side are two additional dials labeled "Matching Switch".
On the back of the instrument, uncovered in the photo, various internal components of the Coulter Counter are visible, including: the vacuum regulator, the mercury manometer, the stopcock control piece, etc.
The next photograph, taken from the removed cover, has a sticker featuring a labeled diagram of the aforementioned internal components. In the same photograph, one can find a second sticker warning the user about shipping an instrument containing mercury, and a third featuring a labeled diagram of "Dual and Triple Manometer Electrical Connections".
The front facade is divided into unequal thirds. The faceplate of the top third is black and features, in the top right corner, the Coulter Counter logo in the middle
of an outlined white rectangle. In the top left corner is a screen which is the same size as the outlined rectangle. Beneath the rectangular screen are two equal sized square screens; these monitors are green and grey and are labeled "Sizing" and "Debris" respectively. The second third is a large rectangular cavity covering the entire right side of the front of the apparatus, beginning below the logo and continuing down near the very bottom. In it, the user has access to the sample-mount apparatus. The final third of the front facade covers the lower left quadrant of the instrument and extends somewhat higher. On the metallic faceplate of this third are featured four dials: at the top, a small one for amplification (the range is from 1/8 to 64, with an "Off" setting); in the middle, two large ones for determining the threshold (the left for the lower threshold and the right for the upper threshold, with both ranging from -10 to 110); and near the bottom, another small one for the aperture current (ranging from 8 to 1/18, with an "off" setting). On the left hand side on a black strip at the very bottom is a power button meant to be pulled "on".
In a long embedded oval near the top of left side of the box is a series of four dials. Presumably these allow the user to adjust the settings for the screen(s). In a smaller embedded oval near the middle of the left side are two additional dials labeled "Matching Switch".
On the back of the instrument, uncovered in the photo, various internal components of the Coulter Counter are visible, including: the vacuum regulator, the mercury manometer, the stopcock control piece, etc.
The next photograph, taken from the removed cover, has a sticker featuring a labeled diagram of the aforementioned internal components. In the same photograph, one can find a second sticker warning the user about shipping an instrument containing mercury, and a third featuring a labeled diagram of "Dual and Triple Manometer Electrical Connections".
Signedon back: COULTER ELECTRONICS, INC.
FunctionA Coulter counter is a device for counting individual bacteria or eukaryotic cells, and roughly determining their size. The solution being studied is drawn with a vacuum pump through an electrically charged tube with a tiny hole at one end. As it passes through the hole, each particle within the solution blocks the electrical field for a moment. The force and frequency of the distortions in voltage can be matched to specific numbers and sizes of particles.
Historical AttributesUsed in John B. Little Physiology Lab, HSPH.
ProvenanceJohn B. Little, Department of Cancer Cell Biology, Harvard School of Public Health; gift to CHSI, 2003.