Aperture Tubes

The aperture is a hollow glass tube with a hole in it through which cells are pulled in the Coulter counter. This tube is filled with salt solution and an electrode is placed on the inside and outside of the tube and electrical current flows through the hole in the tube. When a sample is measured, a vacuum is placed on this inside of the tube that pulls cells or particles through the hole. Every time a cell enters the hole of the aperture it displaces salt solution which results in a visible electrical pulse. The size of the pulse tells you how big the cell (or any particle) was when it went through the hole. The number of pulses tells you how many things went through the hole.

Coulter Aperture Tubes for Multisizer 4e

Aperture (Nominal Diameter, μm)	Particle Diameter Range (μm)				Particle Volume Range (μm3or fL)
	Total	Lower Limit	Upper Standard Limit	Upper Extended Limit	Total	Lower Limit	Upper Standard Limit	Upper Extended Limit	Part Number
10†	0.2 - 8.0	0.2μm	6.0μm	8.0μm	0.004 - 268 x 103μm3	0.004μm3	113μm3	268μm3	B42812
20†	0.4 - 16	0.4μm	12μm	16μm	0.034 - 2.14 x 103μm3	0.034μm3	905μm3	2,144μm3	A36390
30†	0.6 - 24	0.6μm	18μm	24μm	0.113 - 7.24 x 103μm3	0.113μm3	3,053μm3	7,238μm3	A36391
50††	1.0 - 40	1.0μm	30μm	40μm	0.524 - 33.5 x 103μm3	0.524μm3	14,137μm3	33,510μm3	A36392
70††	1.4 - 56	1.4μm	42μm	56μm	1.44 - 92.0 x 103μm3	1.44μm3	38,792μm3	91,952μm3	A36393
100††	2.0 - 80	2.0μm	60μm	80μm	4.19 - 268 x 103μm3	4.19μm3	113 x 103μm3	268 x 103μm3	A36394
140††	2.8 - 112	2.8μm	84μm	112μm	11.5 - 736 x 103μm3	11.5μm3	310 x 103μm3	736 x 103μm3	A36395
200††	4.0 - 160	4.0μm	120μm	160μm	33.5 - 2.14 x 106μm3	33.5μm3	905 x 103μm3	2.14 x 106μm3	A36396
280	5.6 - 224	5.6μm	168μm	224μm	92.0 - 5.88 x 106μm3	92.0μm3	2.48 x 106μm3	5.88 x 106μm3	A36397
400	8.0 - 320	8.0μm	240μm	320μm	268 - 17.2 x 106μm3	268μm3	7.24 x 106μm3	17.2 x 106μm3	A36398
560	11.2 - 448	11.2μm	336μm	448μm	736 - 47.1 x 106μm3	736μm3	19.9 x 106μm3	47.1 x 106μm3	A36399
800†††	16 - 640	16μm	480μm	640μm	2145 - 137 x 106μm3	2145μm3	57.9 x 106μm3	137 x 106μm3	A40889
1000†††	20 - 800	20μm	600μm	800μm	4189 - 268 x 106μm3	4189μm3	113 x 106μm3	268 x 106μm3	A36400
2000†††	40 - 1600	40μm	1200μm	1600μm	33,510-2140 x 106μm3	33,510μm3	905 x 106μm3	2140 x 106μm3	A36401

High resolution tubes have an aperture thickness 120% greater than normal apertures thus, extending the time the particle takes to pass through the aperture, giving greater discrimination of particle size.

Hi-Res 50	1.0 - 40	1.0μm	30μm	40μm	0.524 –33.5x 103μm3	0.524μm3	14,137μm3	33,510 μm3	A44581
Hi-Res 70	1.4 – 56	1.4μm	42μm	56μm	1.44 –92.0x 103μm3	1.44μm3	38,792 μm3	91,952 μm3	A44582
Hi-Res 100	2.0-80	2.0μm	60μm	80μm	4.19 –268x 103μm3	4.19μm3	113x 103μm3	268x 103μm3	A44583
Hi-Res 140	2.8 – 112	2.8μm	84μm	112μm	11.5 –736x 103μm3	11.5μm3	310x 103μm3	736x 103μm3	A44584
Hi-Res 200	4.0 – 160	4.0μm	120μm	160μm	33.5 –2.14 x 106μm3	33.5μm3	905x 103μm3	2.14 x 106μm3	A44585

s † Range depends upon system cleanliness and environmental electromagnetic noise
†† Available in high resolution apertures
††† Range depends upon sample density

Aperture Range
Total range: 2% to 80% of aperture diameter
Standard Range: 2% to 60% of aperture diameter
Extended Range: 60% to 80% of aperture diameter

Aperture Dynamic Range
Standard 1:30 (by diameter), Extended 1:40 (by diameter)
Standard 1:27,000 (by volume), Extended 1:64,000 (by volume)

Microsphere Calibration Standards for Coulter Instruments

Part Number	Name	Nominal Size	Primary Aperture(s) for calibration*	Other Apertures for verification**
6602792	STANDARD 2 µm, LATEX PARTICLE, NIST TRACEABLE	2µm	10 µm	20 µm, 30 µm
6602793	STANDARD 3 µm, LATEX PARTICLE, NIST TRACEABLE	3 µm	20 µm	10 µm, 30 µm
6602794	STANDARD 5 µm, LATEX PARTICLE, NIST TRACEABLE	5 µm	30 µm	10 µm, 20 µm, 50 µm
6602796	STANDARD 10 µm, LATEX PARTICLE, NIST TRACEABLE	10 µm	50 µm, 70 µm	20 µm, 30 µm, 50 µm, 70 µm, 100 µm, 140 µm, 200 µm
6602797	STANDARD 15 µm, LATEX PARTICLE, NIST TRACEABLE	15 µm	70 µm	50 µm, 100 µm, 200 µm, 280 µm
6602798	STANDARD 20 µm, LATEX PARTICLE, NIST TRACEABLE	20 µm	100 µm, 140 µm	140 µm, 200 µm, 280 µm, 400 µm
6602799	STANDARD 30 µm, LATEX PARTICLE, NIST TRACEABLE	30 µm	200 µm	100 µm, 140 µm, 200 µm, 280 µm, 400 µm, 560 µm
6602800	STANDARD 43 µm, LATEX PARTICLE, NIST TRACEABLE	43 µm	280 µm	2800 µm, 400 µm

*Use recommended bead with primary aperture for Aperture Calibration.
**Additional sized beads can be used to verify the performance of the aperture after calibration.
It is recommended to calibrate the instrument using a bead that lies within 7-30% of the aperture size range.

Choosing the Right Instrument
for Cell Counting and Particle Characterization