Abstract: A method and a particle analyzer are provided for determining a particle size distribution of a liquid sample including particles of a lower size range, particles of an intermediate size range, and particles of an upper size range. A dark-field image frame is captured in which the particles of the lower size range and the particles of the intermediate size range are resolved, and a bright-field image frame is captured in which the particles of the intermediate size range and the particles of the upper size range are resolved. Absolute sizes of the particles of the intermediate size range and the particles of the upper size range are determined from the bright-field image frame. Calibrated sizes of the particles of the lower size range are determined from the dark-field image frame by using the particles of the intermediate size range as internal calibration standards.

Abstract: A method and a particle analyzer are provided for determining a particle size distribution of a liquid sample including particles of a lower size range, particles of an intermediate size range, and particles of an upper size range. A dark-field image frame is captured in which the particles of the lower size range and the particles of the intermediate size range are resolved, and a bright-field image frame is captured in which the particles of the intermediate size range and the particles of the upper size range are resolved. Absolute sizes of the particles of the intermediate size range and the particles of the upper size range are determined from the bright-field image frame. Calibrated sizes of the particles of the lower size range are determined from the dark-field image frame by using the particles of the intermediate size range as internal calibration standards.

Abstract: A method and a particle analyzer are provided for determining a particle size distribution of a liquid sample including particles of a lower size range, particles of an intermediate size range, and particles of an upper size range. A dark-field image frame is captured in which the particles of the lower size range and the particles of the intermediate size range are resolved, and a bright-field image frame is captured in which the particles of the intermediate size range and the particles of the upper size range are resolved. Absolute sizes of the particles of the intermediate size range and the particles of the upper size range are determined from the bright-field image frame. Calibrated sizes of the particles of the lower size range are determined from the dark-field image frame by using the particles of the intermediate size range as internal calibration standards.

Abstract: A method and a particle analyzer are provided for determining a particle size distribution of a liquid sample including particles of a lower size range, particles of an intermediate size range, and particles of an upper size range. A dark-field image frame is captured in which the particles of the lower size range and the particles of the intermediate size range are resolved, and a bright-field image frame is captured in which the particles of the intermediate size range and the particles of the upper size range are resolved. Absolute sizes of the particles of the intermediate size range and the particles of the upper size range are determined from the bright-field image frame. Calibrated sizes of the particles of the lower size range are determined from the dark-field image frame by using the particles of the intermediate size range as internal calibration standards.

Abstract: The present invention provides a particle standard including particles having optical properties similar to those of a carrier in which the particles are dispersed, as well as a method of calibrating or validating a subject optical particle analyzer with respect to a reference optical particle analyzer by using the particle standard. In the method, the particle standard is analyzed with the reference optical particle analyzer to obtain a reference particle concentration and a reference particle-size distribution. Analogously, the particle standard is analyzed with the subject optical particle analyzer to obtain a subject particle concentration and a subject particle-size distribution. The subject particle concentration and the subject particle-size distribution are then compared to the reference particle concentration and the reference particle-size distribution, respectively, and the subject optical particle analyzer is adjusted accordingly.

Abstract: The present invention provides a plurality of samples, each of which includes particles of a predetermined particle dimension, within narrow predetermined limits, dispersed in a carrier at a predetermined particle concentration. The predetermined particle dimension and the predetermined particle concentration are the same for each sample. However, advantageously, each sample has a different predetermined ratio of a value of an optical property of the particles to a value of the same optical property of the carrier. The present invention also provides a method for selecting a target sample from the plurality of samples to assess the measurement accuracy or the detection sensitivity of an optical particle analyzer as the predetermined ratio approaches 1.

Abstract: The present invention provides a particle standard including particles having optical properties similar to those of a carrier in which the particles are dispersed, as well as a method of calibrating or validating a subject optical particle analyzer with respect to a reference optical particle analyzer by using the particle standard. In the method, the particle standard is analyzed with the reference optical particle analyzer to obtain a reference particle concentration and a reference particle-size distribution. Analogously, the particle standard is analyzed with the subject optical particle analyzer to obtain a subject particle concentration and a subject particle-size distribution. The subject particle concentration and the subject particle-size distribution are then compared to the reference particle concentration and the reference particle-size distribution, respectively, and the subject optical particle analyzer is adjusted accordingly.

Abstract: A method and apparatus for analyzing particles in a fluid, such as proteinaceous particles in a pharmaceutical formulation intended for parenteral delivery, are disclosed. The method comprises arranging a fluid to form a wide and shallow stream, acquiring a sequence of magnified still images of the stream, and processing said images, so as to highlight images of particles in the flowing fluid. The apparatus includes a light source, a flow cell, a lens with increased depth of view, a detector array, and a processor for acquiring and processing the images of particles in the fluid stream.

Abstract: The present invention provides a plurality of samples, each of which includes particles of a predetermined particle dimension, within narrow predetermined limits, dispersed in a carrier at a predetermined particle concentration. The predetermined particle dimension and the predetermined particle concentration are the same for each sample. However, advantageously, each sample has a different predetermined ratio of a value of an optical property of the particles to a value of the same optical property of the carrier. The present invention also provides a method for selecting a target sample from the plurality of samples to assess the measurement accuracy or the detection sensitivity of an optical particle analyzer as the predetermined ratio approaches 1.

Abstract: A method and apparatus for analyzing particles in a fluid, such as proteinaceous particles in a pharmaceutical formulation intended for parenteral delivery, are disclosed. The method comprises arranging a fluid to form a wide and shallow stream, acquiring a sequence of magnified still images of the stream, and processing said images, so as to highlight images of particles in the flowing fluid. The apparatus includes a light source, a flow cell, a lens with increased depth of view, a detector array, and a processor for acquiring and processing the images of particles in the fluid stream.