Abstract

We describe a model-based instrument design combined with a statistical classification approach for the development and realization of high speed cell classification systems based on light scatter. In our work, angular light scatter from cells of four bacterial species of interest, Bacillus subtilis, Escherichia coli, Listeria innocua, and Enterococcus faecalis, was modeled using the discrete dipole approximation. We then optimized a scattering detector array design subject to some hardware constraints, configured the instrument, and gathered experimental data from the relevant bacterial cells. Using these models and experiments, it is shown that optimization using a nominal bacteria model (i.e., using a representative size and refractive index) is insufficient for classification of most bacteria in realistic applications. Hence the computational predictions were constituted in the form of scattering-data-vector distributions that accounted for expected variability in the physical properties between individual bacteria within the four species. After the detectors were optimized using the numerical results, they were used to measure scatter from both the known control samples and unknown bacterial cells. A multivariate statistical method based on a support vector machine (SVM) was used to classify the bacteria species based on light scatter signatures. In our final instrument, we realized correct classification of B. subtilis in the presence of E. coli, L. innocua, and E. faecalis using SVM at 99.1%, 99.6%, and 98.5%, respectively, in the optimal detector array configuration. For comparison, the corresponding values for another set of angles were only 69.9%, 71.7%, and 70.2% using SVM, and more importantly, this improved performance is consistent with classification predictions.

© 2008 Optical Society of America

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References

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  1. G. C. Salzman, S. B. Singham, R. G. Johnston, and C. F. Bohren, "Light scattering and cytometry," in Flow Cytometry and Sorting, 2nd ed. (Wiley, 1990).
  2. A. G. Hoekstra, R. M. P. Doornbos, K. E. I. Deurloo, H. J. Noordmans, B. G. de Grooth, and P. M. A. Sloot, "Another face of Lorenz--Mie scattering: monodisperse distributions of spheres produce Lissajous-like patterns," Appl. Opt. 33, 494-500 (1994).
    [CrossRef] [PubMed]
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    [CrossRef] [PubMed]
  5. J. R. Mourant, J. P. Freyer, A. H. Hielscher, A. A. Eick, D. Shen, and T. M. Johnson, "Mechanisms of light scattering from biological cells relevant to noninvasive optical-tissue diagnostics," Appl. Opt. 37, 3586-3593 (1998).
    [CrossRef]
  6. B. J. Price, V. H. Kollman, and G. C. Salzman, "Light-scatter analysis of microalgae. Correlation of scatter patterns from pure and mixed asynchronous cultures," Biophys. J. 22, 29-36 (1978).
    [CrossRef] [PubMed]
  7. A. V. Chernyshev, V. I. Prots, A. A. Doroshkin, and V. P. Maltsev, "Particle classification from light scattering with the scanning flow cytometer," Cytometry 37, 215-220 (1999).
    [CrossRef] [PubMed]
  8. M. Venkatapathi, G. Gregori, K. Ragheb, J. P. Robinson, and E. D. Hirleman, "Measurement and analysis of angle resolved scatter from small particles in a cylindrical microchannel," Appl. Opt. 45, 2222-2232 (2006).
    [CrossRef] [PubMed]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
  14. B. M. Nebeker, G. W. Starr, and E. D. Hirleman, "Evaluation of iteration methods used when modeling scattering from features on surfaces using the discrete-dipole approximation," J. Quant. Spectrosc. Radiat. Transf. 60, 493-500 (1998).
    [CrossRef]
  15. B. M. Nebeker, J. L. de la Pena, and E. D. Hirleman, "Comparisons of the discrete-dipole approximation to modified double interaction model methods to predict light scattering from small features on surfaces," J. Quant. Spectrosc. Radiat. Transf. 70, 749-759 (2001).
    [CrossRef]
  16. A. Gupta, D. Akin, and R. Bashir, "Detection of bacterial cells and antibodies using surface micromachined thin silicon cantilever resonators," J. Vac. Sci. Technol. B 22, 2785-2791 (2004).
    [CrossRef]
  17. A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
    [CrossRef] [PubMed]
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    [CrossRef] [PubMed]
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  21. V. Vapnik, Statistical Learning Theory (Wiley, 1998).

2006 (1)

2005 (1)

2004 (1)

A. Gupta, D. Akin, and R. Bashir, "Detection of bacterial cells and antibodies using surface micromachined thin silicon cantilever resonators," J. Vac. Sci. Technol. B 22, 2785-2791 (2004).
[CrossRef]

2001 (1)

B. M. Nebeker, J. L. de la Pena, and E. D. Hirleman, "Comparisons of the discrete-dipole approximation to modified double interaction model methods to predict light scattering from small features on surfaces," J. Quant. Spectrosc. Radiat. Transf. 70, 749-759 (2001).
[CrossRef]

2000 (2)

A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
[CrossRef] [PubMed]

C. Signoretto, M. del Mar Lleò, M. C. Tafi, and P. Canepari, "Cell wall chemical composition of Enterococcus faecalis in the viable but nonculturable state," Appl. Environ. Microbiol. 66, 1953-1959 (2000).
[CrossRef] [PubMed]

1999 (1)

A. V. Chernyshev, V. I. Prots, A. A. Doroshkin, and V. P. Maltsev, "Particle classification from light scattering with the scanning flow cytometer," Cytometry 37, 215-220 (1999).
[CrossRef] [PubMed]

1998 (2)

J. R. Mourant, J. P. Freyer, A. H. Hielscher, A. A. Eick, D. Shen, and T. M. Johnson, "Mechanisms of light scattering from biological cells relevant to noninvasive optical-tissue diagnostics," Appl. Opt. 37, 3586-3593 (1998).
[CrossRef]

B. M. Nebeker, G. W. Starr, and E. D. Hirleman, "Evaluation of iteration methods used when modeling scattering from features on surfaces using the discrete-dipole approximation," J. Quant. Spectrosc. Radiat. Transf. 60, 493-500 (1998).
[CrossRef]

1997 (1)

1995 (1)

1994 (1)

1993 (1)

1988 (1)

B. T. Draine, "The discrete-dipole approximation and its application to interstellar graphite grains," Astrophys. J. 333, 848-872 (1988).
[CrossRef]

1978 (1)

B. J. Price, V. H. Kollman, and G. C. Salzman, "Light-scatter analysis of microalgae. Correlation of scatter patterns from pure and mixed asynchronous cultures," Biophys. J. 22, 29-36 (1978).
[CrossRef] [PubMed]

1973 (1)

E. M. Purcell and C. R. Pennypacker, "Scattering and absorption of light by nonspherical dielectric grains," Astrophys. J. 186, 705-714 (1973).
[CrossRef]

1970 (1)

P. J. Wyatt, "Cell wall thickness, size distribution, refractive index ratio and dry weight content of living bacteria (Staphylococcus aureus)," Nature 226, 277-279 (1970).
[CrossRef] [PubMed]

1969 (1)

A. P. Kononenko, K. I. Kononenko, and D. M. Mikhov, "Dependence of refractive index on physiological state of microbial population," J. Appl. Spectros. 11, 795-797 (1969).
[CrossRef]

Akin, D.

A. Gupta, D. Akin, and R. Bashir, "Detection of bacterial cells and antibodies using surface micromachined thin silicon cantilever resonators," J. Vac. Sci. Technol. B 22, 2785-2791 (2004).
[CrossRef]

Alfano, R. R.

Alimova, A.

Bashir, R.

A. Gupta, D. Akin, and R. Bashir, "Detection of bacterial cells and antibodies using surface micromachined thin silicon cantilever resonators," J. Vac. Sci. Technol. B 22, 2785-2791 (2004).
[CrossRef]

Bohren, C. F.

G. C. Salzman, S. B. Singham, R. G. Johnston, and C. F. Bohren, "Light scattering and cytometry," in Flow Cytometry and Sorting, 2nd ed. (Wiley, 1990).

C. F. Bohren and D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley Interscience, 1983).

Canepari, P.

C. Signoretto, M. del Mar Lleò, M. C. Tafi, and P. Canepari, "Cell wall chemical composition of Enterococcus faecalis in the viable but nonculturable state," Appl. Environ. Microbiol. 66, 1953-1959 (2000).
[CrossRef] [PubMed]

Chernyshev, A. V.

A. V. Chernyshev, V. I. Prots, A. A. Doroshkin, and V. P. Maltsev, "Particle classification from light scattering with the scanning flow cytometer," Cytometry 37, 215-220 (1999).
[CrossRef] [PubMed]

de Grooth, B. G.

de la Pena, J. L.

B. M. Nebeker, J. L. de la Pena, and E. D. Hirleman, "Comparisons of the discrete-dipole approximation to modified double interaction model methods to predict light scattering from small features on surfaces," J. Quant. Spectrosc. Radiat. Transf. 70, 749-759 (2001).
[CrossRef]

del Mar Lleò, M.

C. Signoretto, M. del Mar Lleò, M. C. Tafi, and P. Canepari, "Cell wall chemical composition of Enterococcus faecalis in the viable but nonculturable state," Appl. Environ. Microbiol. 66, 1953-1959 (2000).
[CrossRef] [PubMed]

Deurloo, K. E. I.

Doornbos, R. M. P.

Doroshkin, A. A.

A. V. Chernyshev, V. I. Prots, A. A. Doroshkin, and V. P. Maltsev, "Particle classification from light scattering with the scanning flow cytometer," Cytometry 37, 215-220 (1999).
[CrossRef] [PubMed]

Draine, B. T.

B. T. Draine, "The discrete-dipole approximation and its application to interstellar graphite grains," Astrophys. J. 333, 848-872 (1988).
[CrossRef]

Eick, A. A.

Freyer, J. P.

Gottlieb, P.

Gregori, G.

Gupta, A.

A. Gupta, D. Akin, and R. Bashir, "Detection of bacterial cells and antibodies using surface micromachined thin silicon cantilever resonators," J. Vac. Sci. Technol. B 22, 2785-2791 (2004).
[CrossRef]

Hielscher, A. H.

Hirleman, E. D.

M. Venkatapathi, G. Gregori, K. Ragheb, J. P. Robinson, and E. D. Hirleman, "Measurement and analysis of angle resolved scatter from small particles in a cylindrical microchannel," Appl. Opt. 45, 2222-2232 (2006).
[CrossRef] [PubMed]

B. M. Nebeker, J. L. de la Pena, and E. D. Hirleman, "Comparisons of the discrete-dipole approximation to modified double interaction model methods to predict light scattering from small features on surfaces," J. Quant. Spectrosc. Radiat. Transf. 70, 749-759 (2001).
[CrossRef]

B. M. Nebeker, G. W. Starr, and E. D. Hirleman, "Evaluation of iteration methods used when modeling scattering from features on surfaces using the discrete-dipole approximation," J. Quant. Spectrosc. Radiat. Transf. 60, 493-500 (1998).
[CrossRef]

R. Schmehl, B. M. Nebeker, and E. D. Hirleman, "Discrete-dipole approximation for scattering by features on surfaces by means of a two-dimensional fast Fourier transform technique," J. Opt. Soc. Am. A 14, 3026-3036 (1997).
[CrossRef]

Hoekstra, A. G.

Huffman, D. R.

C. F. Bohren and D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley Interscience, 1983).

Johnson, T. M.

Johnston, R. G.

G. C. Salzman, S. B. Singham, R. G. Johnston, and C. F. Bohren, "Light scattering and cytometry," in Flow Cytometry and Sorting, 2nd ed. (Wiley, 1990).

Katz, A.

Kochneva, G. V.

A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
[CrossRef] [PubMed]

Kollman, V. H.

B. J. Price, V. H. Kollman, and G. C. Salzman, "Light-scatter analysis of microalgae. Correlation of scatter patterns from pure and mixed asynchronous cultures," Biophys. J. 22, 29-36 (1978).
[CrossRef] [PubMed]

Kononenko, A. P.

A. P. Kononenko, K. I. Kononenko, and D. M. Mikhov, "Dependence of refractive index on physiological state of microbial population," J. Appl. Spectros. 11, 795-797 (1969).
[CrossRef]

Kononenko, K. I.

A. P. Kononenko, K. I. Kononenko, and D. M. Mikhov, "Dependence of refractive index on physiological state of microbial population," J. Appl. Spectros. 11, 795-797 (1969).
[CrossRef]

Lock, J. A.

Maltsev, V. P.

A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
[CrossRef] [PubMed]

A. V. Chernyshev, V. I. Prots, A. A. Doroshkin, and V. P. Maltsev, "Particle classification from light scattering with the scanning flow cytometer," Cytometry 37, 215-220 (1999).
[CrossRef] [PubMed]

Mikhov, D. M.

A. P. Kononenko, K. I. Kononenko, and D. M. Mikhov, "Dependence of refractive index on physiological state of microbial population," J. Appl. Spectros. 11, 795-797 (1969).
[CrossRef]

Mourant, J. R.

Nebeker, B. M.

B. M. Nebeker, J. L. de la Pena, and E. D. Hirleman, "Comparisons of the discrete-dipole approximation to modified double interaction model methods to predict light scattering from small features on surfaces," J. Quant. Spectrosc. Radiat. Transf. 70, 749-759 (2001).
[CrossRef]

B. M. Nebeker, G. W. Starr, and E. D. Hirleman, "Evaluation of iteration methods used when modeling scattering from features on surfaces using the discrete-dipole approximation," J. Quant. Spectrosc. Radiat. Transf. 60, 493-500 (1998).
[CrossRef]

R. Schmehl, B. M. Nebeker, and E. D. Hirleman, "Discrete-dipole approximation for scattering by features on surfaces by means of a two-dimensional fast Fourier transform technique," J. Opt. Soc. Am. A 14, 3026-3036 (1997).
[CrossRef]

Noordmans, H. J.

Pennypacker, C. R.

E. M. Purcell and C. R. Pennypacker, "Scattering and absorption of light by nonspherical dielectric grains," Astrophys. J. 186, 705-714 (1973).
[CrossRef]

Petrov, A. K.

A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
[CrossRef] [PubMed]

Price, B. J.

B. J. Price, V. H. Kollman, and G. C. Salzman, "Light-scatter analysis of microalgae. Correlation of scatter patterns from pure and mixed asynchronous cultures," Biophys. J. 22, 29-36 (1978).
[CrossRef] [PubMed]

Prots, V. I.

A. V. Chernyshev, V. I. Prots, A. A. Doroshkin, and V. P. Maltsev, "Particle classification from light scattering with the scanning flow cytometer," Cytometry 37, 215-220 (1999).
[CrossRef] [PubMed]

Purcell, E. M.

E. M. Purcell and C. R. Pennypacker, "Scattering and absorption of light by nonspherical dielectric grains," Astrophys. J. 186, 705-714 (1973).
[CrossRef]

Ragheb, K.

Robinson, J. P.

Rudolph, E.

Salzman, G. C.

B. J. Price, V. H. Kollman, and G. C. Salzman, "Light-scatter analysis of microalgae. Correlation of scatter patterns from pure and mixed asynchronous cultures," Biophys. J. 22, 29-36 (1978).
[CrossRef] [PubMed]

G. C. Salzman, S. B. Singham, R. G. Johnston, and C. F. Bohren, "Light scattering and cytometry," in Flow Cytometry and Sorting, 2nd ed. (Wiley, 1990).

Schmehl, R.

Shen, D.

Shvalov, A. N.

A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
[CrossRef] [PubMed]

Signoretto, C.

C. Signoretto, M. del Mar Lleò, M. C. Tafi, and P. Canepari, "Cell wall chemical composition of Enterococcus faecalis in the viable but nonculturable state," Appl. Environ. Microbiol. 66, 1953-1959 (2000).
[CrossRef] [PubMed]

Singham, S. B.

G. C. Salzman, S. B. Singham, R. G. Johnston, and C. F. Bohren, "Light scattering and cytometry," in Flow Cytometry and Sorting, 2nd ed. (Wiley, 1990).

Sivolobova, G. F.

A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
[CrossRef] [PubMed]

Sloot, P. M. A.

Soini, J. T.

A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
[CrossRef] [PubMed]

Starr, G. W.

B. M. Nebeker, G. W. Starr, and E. D. Hirleman, "Evaluation of iteration methods used when modeling scattering from features on surfaces using the discrete-dipole approximation," J. Quant. Spectrosc. Radiat. Transf. 60, 493-500 (1998).
[CrossRef]

Steiner, J. C.

Surovtsev, I. V.

A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
[CrossRef] [PubMed]

Tafi, M. C.

C. Signoretto, M. del Mar Lleò, M. C. Tafi, and P. Canepari, "Cell wall chemical composition of Enterococcus faecalis in the viable but nonculturable state," Appl. Environ. Microbiol. 66, 1953-1959 (2000).
[CrossRef] [PubMed]

Taubenblatt, M. A.

Tran, T. K.

Vapnik, V.

V. Vapnik, Statistical Learning Theory (Wiley, 1998).

Venkatapathi, M.

Wyatt, P. J.

P. J. Wyatt, "Cell wall thickness, size distribution, refractive index ratio and dry weight content of living bacteria (Staphylococcus aureus)," Nature 226, 277-279 (1970).
[CrossRef] [PubMed]

Xu, M.

Appl. Environ. Microbiol. (1)

C. Signoretto, M. del Mar Lleò, M. C. Tafi, and P. Canepari, "Cell wall chemical composition of Enterococcus faecalis in the viable but nonculturable state," Appl. Environ. Microbiol. 66, 1953-1959 (2000).
[CrossRef] [PubMed]

Appl. Opt. (3)

Astrophys. J. (2)

E. M. Purcell and C. R. Pennypacker, "Scattering and absorption of light by nonspherical dielectric grains," Astrophys. J. 186, 705-714 (1973).
[CrossRef]

B. T. Draine, "The discrete-dipole approximation and its application to interstellar graphite grains," Astrophys. J. 333, 848-872 (1988).
[CrossRef]

Biophys. J. (1)

B. J. Price, V. H. Kollman, and G. C. Salzman, "Light-scatter analysis of microalgae. Correlation of scatter patterns from pure and mixed asynchronous cultures," Biophys. J. 22, 29-36 (1978).
[CrossRef] [PubMed]

Cytometry (2)

A. V. Chernyshev, V. I. Prots, A. A. Doroshkin, and V. P. Maltsev, "Particle classification from light scattering with the scanning flow cytometer," Cytometry 37, 215-220 (1999).
[CrossRef] [PubMed]

A. N. Shvalov, J. T. Soini, I. V. Surovtsev, G. V. Kochneva, G. F. Sivolobova, A. K. Petrov, and V. P. Maltsev, "Individual Escherichia coli cells studied from light scattering with the scanning flow cytometer," Cytometry 41, 41-45 (2000).
[CrossRef] [PubMed]

J. Appl. Spectros. (1)

A. P. Kononenko, K. I. Kononenko, and D. M. Mikhov, "Dependence of refractive index on physiological state of microbial population," J. Appl. Spectros. 11, 795-797 (1969).
[CrossRef]

J. Opt. Soc. Am. A (3)

J. Quant. Spectrosc. Radiat. Transf. (2)

B. M. Nebeker, G. W. Starr, and E. D. Hirleman, "Evaluation of iteration methods used when modeling scattering from features on surfaces using the discrete-dipole approximation," J. Quant. Spectrosc. Radiat. Transf. 60, 493-500 (1998).
[CrossRef]

B. M. Nebeker, J. L. de la Pena, and E. D. Hirleman, "Comparisons of the discrete-dipole approximation to modified double interaction model methods to predict light scattering from small features on surfaces," J. Quant. Spectrosc. Radiat. Transf. 70, 749-759 (2001).
[CrossRef]

J. Vac. Sci. Technol. B (1)

A. Gupta, D. Akin, and R. Bashir, "Detection of bacterial cells and antibodies using surface micromachined thin silicon cantilever resonators," J. Vac. Sci. Technol. B 22, 2785-2791 (2004).
[CrossRef]

Nature (1)

P. J. Wyatt, "Cell wall thickness, size distribution, refractive index ratio and dry weight content of living bacteria (Staphylococcus aureus)," Nature 226, 277-279 (1970).
[CrossRef] [PubMed]

Opt. Lett. (1)

Other (3)

V. Vapnik, Statistical Learning Theory (Wiley, 1998).

G. C. Salzman, S. B. Singham, R. G. Johnston, and C. F. Bohren, "Light scattering and cytometry," in Flow Cytometry and Sorting, 2nd ed. (Wiley, 1990).

C. F. Bohren and D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley Interscience, 1983).

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Figures (6)

Fig. 1
Fig. 1

(Color online) Schematic of the flow cytometer system used in experiments.

Fig. 2
Fig. 2

(Color online) Forward scattering signatures for representative bacteria of the four species of interest, plotted as average differential scattering cross section (dCsc∕dω averaged over φ) versus forward scattering angle θ. The vertical lines indicate the center angles for the four ring apertures in the detector array. The two sets of four lines correspond to the two different measurement configurations, A (diamond ends) and B (circular ends).

Fig. 3
Fig. 3

(Color online) Variation of distinguishability with forward angle θ (averaged over all azimuth angles f) for representative bacteria of the four species. The two sets of four vertical lines correspond to the two different measurement configurations, A (diamond ends) and B (circular ends).

Fig. 4
Fig. 4

(Color online) Predicted scatter plots of ring-averaged forward scattering intensities (average dCsc / over f) for detector configuration A for four bacterial species (note: size of subgroups are not to scale). Each data point represents the predicted signal pair for bacteria from a population distribution governed by Eq. (2) with the following:refractive index mean of 1.394 and standard deviation of 2 % and a normal volume distribution with standard deviation of 5 % .

Fig. 5
Fig. 5

(Color online) Predicted scatter plots of ring-averaged forward scattering intensities (average dCsc / over f) for detector configuration B for four bacterial species (note: sizes of subgroups are not to scale). Each data point represents the predicted signal pair for bacteria from a population distribution governed by Eq. (2) with the following:refractive index mean of 1.394 and standard deviation of 2 % and a normal volume distribution with standard deviation of 5%.

Fig. 6
Fig. 6

(Color online) Scatter measurements of B. subtilis and E. faecalis (forward scatter was integrated from 7° to 23° and side scatter integrated from 80° to 100° as used in conventional flow cytometry).

Tables (2)

Tables Icon

Table 1 Performance Predictions for Advanced Cytometers based on Multiangle Scatter Detector Configurations A and B a

Tables Icon

Table 2 Classification Rates of Bacteria for Multiangle Light Scatter Detector Configurations A and B

Equations (2)

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D = 4 a n g l e s | ( d C s c i d C s c j ) / ( d C s c i + d C s c j ) | ,
w i j = subgroup 1 σ n 2 π exp [ ( n i n o ) 2 2 σ n 2 ] × 1 σ v 2 π exp [ ( V j V o ) 2 2 σ v 2 ] ,

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