Concentration Analysis
Concentration Analysis “A rapid and precise method of measuring particle concentrations for both biological and synthetic samples.”
A key feature of the qNano and qViro-X systems is the ability to easily and precisely determine particle concentration through the use of nanopore-based sensing. A wide range of particle sizes can be measured, extending beyond the capabilities of techniques such as flow cytometry and coulter counters. Particles are directly counted which avoids approximations, such as those necessary for turbidity measurements. Concentrations ranging from 105 to greater than 1012 particles per mL can be measured.
As particle blockade frequency (particle flow rate) is proportional to sample concentration, the change in frequency with applied pressure is used to quantitatively determine dispersion concentrations.1 Concentration measurements are carried out by recording the particle count rate at different applied pressures with the same applied electric field and pore size (Figure 1). The device is calibrated by comparing the blockade event frequency of a known concentration standard to the blockade pulse frequency of the unknown sample.2 1. Roberts, G.S., Yu, S., Zeng, Q., Chan, L.C.L., Anderson, W., Colby, A.H., Grinstaff, M.W., Reid, S., Vogel, R., Tunable Pores for Measuring Concentrations of Synthetic and Biological Nanoparticle Dispersions, Biosensors and Bioelectronics 31, pp. 17-25, (2012). 2. Roberts et al. have demonstrated that event frequency scales linearly with applied pressure and concentration, and that measured concentrations are independent of particle type and size.
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Example: Concentration of Biological Samples In the example below, from Roberts et al. (2012), the qNano was applied to measure concentrations of baculovirus occlusion bodies (diameter of ~1 μm) and the marine photosynthetic cyanobacterium Prochlorococcus, (diameter of ~600 nm). The determined concentrations agree well with results from counting with microscopy (17% difference between mean concentrations) and flow cytometry (6% difference between mean concentrations), respectively.
Population %
1500
Particle count rate (counts/min)
Baculoviruvs
8
1200
Calibration
6
• Nanopore-based sensors provide a rapid, sensitive detection technique for concentration determination of biological and synthetic particle samples. • 50 nm – 10 μm sized particles can be measured, which extends beyond the range of conventional coulter counters and flow cytometers. • A wide concentration range is covered, extending from 105 to 1012 particles per mL. • There is no need for pre-treatment of samples, which means biological samples, such as viruses and bacteria can be rapidly assessed.
10 1800
Key Features
4
• Additional parameters (size and charge of particles) are simultaneously determined.
2 0
0.5
1.0
1.5
2.0
2.5
Particle size (µm)
900
REFERENCE: G. Seth Roberts, Sam Yu, Qinglu Zeng, Leslie C.L. Chan, Will Anderson, Aaron H. Colby, Mark W. Grinstaff, Steven Reid, Robert Vogel. “Tunable
600
Pores for Measuring Concentrations of Synthetic and Biological Nanoparticle Dispersions” Biosensors and Bioelectronics, 31 pp. 17-25, (2012).
300
0 0.0
0.2
0.4
0.6
0.8
1.0
Applied pressure (kPa)
Figure 1. Concentration determination for Baculovirus occlusion bodies (inset shows particle size distribution). The viral concentration calculated using a comparison between the plotted gradients was (9.9 ± 0.8) ×107 particles / mL.
Particle count rate (counts/min)
200 180
Prochlorococcus MED4
10 Population %
220
160
Calibration
8 6 4 2 0 200 400 600 800 1000 1200
140
Particle size (µm)
120 100 80 60 40 20 0 0.0
0.2
0.4
0.6
0.8
1.0
1.2
Applied pressure (kPa)
Figure 2. Concentration determination for Prochlorococcus marine bacteria (inset shows particle size distribution). Mean measured concentration was (6.0 ±0.4) ×108 particles / mL.
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HEAD OFFICE 175 Roydvale Avenue, Burnside, Christchurch 8053, New Zealand Phone +64-3-357-4270 Fax+64-3-357-4273
Enquire at [email protected] and ask how we can improve the quality of your particle analysis research.
UK / EUROPE The Oxford Science Park, Magdalen Centre, Robert Robinson Avenue, Oxford OX4 4GA, United Kingdom Phone +44-1865-309-666
UNITED STATES 85 Bolton Street, Cambridge MA 02140, United States Phone +1-617-945-5936 Fax +1-857-259-6623
A key feature of the qNano and qViro-X systems is the ability to easily and precisely determine particle concentration through the use of nanopore-based sensing. A wide range of particle sizes can be measured, extending beyond the capabilities of techniques such as flow cytometry and coulter counters. Particles are directly counted which avoids approximations, such as those necessary for turbidity measurements. Concentrations ranging from 105 to greater than 1012 particles per mL can be measured.
As particle blockade frequency (particle flow rate) is proportional to sample concentration, the change in frequency with applied pressure is used to quantitatively determine dispersion concentrations.1 Concentration measurements are carried out by recording the particle count rate at different applied pressures with the same applied electric field and pore size (Figure 1). The device is calibrated by comparing the blockade event frequency of a known concentration standard to the blockade pulse frequency of the unknown sample.2 1. Roberts, G.S., Yu, S., Zeng, Q., Chan, L.C.L., Anderson, W., Colby, A.H., Grinstaff, M.W., Reid, S., Vogel, R., Tunable Pores for Measuring Concentrations of Synthetic and Biological Nanoparticle Dispersions, Biosensors and Bioelectronics 31, pp. 17-25, (2012). 2. Roberts et al. have demonstrated that event frequency scales linearly with applied pressure and concentration, and that measured concentrations are independent of particle type and size.
www.izon.com
Example: Concentration of Biological Samples In the example below, from Roberts et al. (2012), the qNano was applied to measure concentrations of baculovirus occlusion bodies (diameter of ~1 μm) and the marine photosynthetic cyanobacterium Prochlorococcus, (diameter of ~600 nm). The determined concentrations agree well with results from counting with microscopy (17% difference between mean concentrations) and flow cytometry (6% difference between mean concentrations), respectively.
Population %
1500
Particle count rate (counts/min)
Baculoviruvs
8
1200
Calibration
6
• Nanopore-based sensors provide a rapid, sensitive detection technique for concentration determination of biological and synthetic particle samples. • 50 nm – 10 μm sized particles can be measured, which extends beyond the range of conventional coulter counters and flow cytometers. • A wide concentration range is covered, extending from 105 to 1012 particles per mL. • There is no need for pre-treatment of samples, which means biological samples, such as viruses and bacteria can be rapidly assessed.
10 1800
Key Features
4
• Additional parameters (size and charge of particles) are simultaneously determined.
2 0
0.5
1.0
1.5
2.0
2.5
Particle size (µm)
900
REFERENCE: G. Seth Roberts, Sam Yu, Qinglu Zeng, Leslie C.L. Chan, Will Anderson, Aaron H. Colby, Mark W. Grinstaff, Steven Reid, Robert Vogel. “Tunable
600
Pores for Measuring Concentrations of Synthetic and Biological Nanoparticle Dispersions” Biosensors and Bioelectronics, 31 pp. 17-25, (2012).
300
0 0.0
0.2
0.4
0.6
0.8
1.0
Applied pressure (kPa)
Figure 1. Concentration determination for Baculovirus occlusion bodies (inset shows particle size distribution). The viral concentration calculated using a comparison between the plotted gradients was (9.9 ± 0.8) ×107 particles / mL.
Particle count rate (counts/min)
200 180
Prochlorococcus MED4
10 Population %
220
160
Calibration
8 6 4 2 0 200 400 600 800 1000 1200
140
Particle size (µm)
120 100 80 60 40 20 0 0.0
0.2
0.4
0.6
0.8
1.0
1.2
Applied pressure (kPa)
Figure 2. Concentration determination for Prochlorococcus marine bacteria (inset shows particle size distribution). Mean measured concentration was (6.0 ±0.4) ×108 particles / mL.
www.izon.com
HEAD OFFICE 175 Roydvale Avenue, Burnside, Christchurch 8053, New Zealand Phone +64-3-357-4270 Fax+64-3-357-4273
Enquire at [email protected] and ask how we can improve the quality of your particle analysis research.
UK / EUROPE The Oxford Science Park, Magdalen Centre, Robert Robinson Avenue, Oxford OX4 4GA, United Kingdom Phone +44-1865-309-666
UNITED STATES 85 Bolton Street, Cambridge MA 02140, United States Phone +1-617-945-5936 Fax +1-857-259-6623
