Quantitation and differentiation of bioparticles based on the measurements of light-scattering signals with a common spectrofluorometer.
By simultaneously scanning both the excitation and emission monochromators of a common spectrofluorometer with same starting excitation and emission wavelength (namely, Delta lambda = 0), we obtained synchronous light scattering (SLS) signals that related to Rayleigh and Mie scatterings. It was found that the SLS signals could be applied for quantitation and differentiation of model bioparticles such as Saccharomyces cerevisiae, Schizosaccharomyces pombe, Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Bacillus thuringiensis and Bacillus megaterium. In PBS buffer, these model bioparticles could form colloidal suspensions or dispersions of sizes ranging from hundreds of nanometers to tens of micrometers, giving SLS signals with the intensity being proportional to the amount of bioparticles in the range from 1.7 x 10 (5) to 1.7 x 10 (9) CFU/mL. A further finding is that polarized synchronous light scattering (PSLS) signals of I 0 degrees -30 degrees against I 0 degrees -0 degrees , which could be obtained by introducing polarizing sheets accessory of the spectrofluorometer, and the derivative synchronous light scattering (DrSLS) signals, which could be obtained directly with the extension function of the spectrofluorometer, offer differentiation information of bioparticles connected with their size, shape, refractive indexes, and inner structure. Refractive indexes of spherical bacteria were then calculated based on light scattering signals.
Huang
Cheng Zhi
CZ
College of Chemistry and Chemical Engineering, MOE Key Laboratory for Luminescence and Real-Time Analysis, CQKL-LTRA, Southwest University, Chongqing, China. chengzhi@swu.edu.cn
Chen
Shao Fen
SF
D001410:Bacillus megaterium / Q000737:chemistry / Q000166:cytology; D001412:Bacillus subtilis / Q000737:chemistry / Q000166:cytology; D001413:Bacillus thuringiensis / Q000737:chemistry / Q000166:cytology; D001419:Bacteria / Q000737:chemistry / Q000166:cytology*; D002021:Buffers; D004926:Escherichia coli / Q000737:chemistry / Q000166:cytology; D008863:Microspheres; D010316:Particle Size; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000166:cytology; D012542:Scattering, Radiation; D012568:Schizosaccharomyces / Q000737:chemistry / Q000166:cytology; D013050:Spectrometry, Fluorescence; D013211:Staphylococcus aureus / Q000737:chemistry / Q000166:cytology
D002021:Buffers