Abstract: Disclosed is a sheath delivery system that uses a continuous flow of sheath fluid into a pressurized internal reservoir that substantially matches the outflow of sheath fluid through the nozzle of a flow cytometer. A substantially constant level of the sheath fluid is maintained. If the sheath fluid level falls below a desired level, or goes above a desired level, a dampened control system is used to reach the desired level. In addition, air pressure in the pressurized internal container is controlled so that an external sheath container can be removed and refilled with additional sheath fluid without stopping the sheath delivery system 100. Differences in pressure are detected by a droplet camera, which measures the droplet breakoff point to determine the pressure of the sheath fluid in the nozzle.

Abstract: Methods and systems for pumping fluid through tubing are provided. Methods include orbiting one or more first rollers at multiple angular speeds around the periphery of a substantially circular first disk having a first radius with each first roller travelling at the same angular speed as the other first rollers, orbiting second rollers at a second angular speed around a substantially circular second disk having substantially the first radius, and increasing the pressure of fluid in tubing between one first roller and one second roller by causing the one or more first rollers to orbit at a first angular speed greater than the second angular speed so the one first roller moves along and fully compresses the tubing in a first section of the first disk, and simultaneously causing the one second roller to move along and fully compress the tubing in a first section of the second disk.

Abstract: Disclosed is an automated method and apparatus for automatically setting a drop delay period by detecting calibration particles in a waste stream. The drop delay is incremented over a series of drop delays and the number of calibration particles in the waste stream is detected for each drop delay. The drop delay is selected which has the least number of calibration particles in the waste stream.

Abstract: Disclosed is a system and method for characterizing optical filters in a flow cytometer and optionally checking the operation of detectors in the flow cytometer. In some embodiments, the system may utilize an LED board having an opening through which the fluorescence and side scatter beams, rays, or images pass and light emitting diodes around the opening that emit light having different spectral profiles. The different spectral profiles allow the system to identify the optical filters that are placed in the flow cytometer, to verify detector operation, to assist in instrumentation troubleshooting, and to provide a quantitative reference for detector comparison.

Abstract: A method and apparatus for pumping fluid through tubing are provided. The method includes orbiting first rollers around the periphery of a first disk at a first tangential speed in a first angular sector and a slower, second tangential speed in a second angular sector, orbiting second rollers around the periphery of a second disk at the second tangential speed, and increasing the pressure of fluid in tubing between one first roller and one second roller by causing the one first roller to fully compress the tubing at the first tangential speed and simultaneously causing the one second roller to fully compress the tubing at the second tangential speed. The apparatus includes a first disk with a recess in its periphery, the first angular sector with a nominal first radius, and a second angular sector with a nominal second radius; and a second disk with the nominal first radius and a recess in its periphery.

Abstract: Disclosed is a system and method for characterizing optical filters in a flow cytometer and optionally checking the operation of detectors in the flow cytometer. In some embodiments, the system may utilize an LED board having an opening through which the fluorescence and side scatter beams, rays, or images pass and light emitting diodes around the opening that emit light having different spectral profiles. The different spectral profiles allow the system to identify the optical filters that are placed in the flow cytometer, to verify detector operation, to assist in instrumentation troubleshooting, and to provide a quantitative reference for detector comparison.

Abstract: Disclosed is a system and method for characterizing optical filters in a flow cytometer and optionally checking the operation of detectors in the flow cytometer. In some embodiments, the system may utilize an LED board having an opening through which the fluorescence and side scatter beams, rays, or images pass and light emitting diodes around the opening that emit light having different spectral profiles. The different spectral profiles allow the system to identify the optical filters that are placed in the flow cytometer, to verify detector operation, to assist in instrumentation troubleshooting, and to provide a quantitative reference for detector comparison.

Abstract: Disclosed is a sheath delivery system that uses a continuous flow of sheath fluid into a pressurized internal reservoir that substantially matches the outflow of sheath fluid through the nozzle of a flow cytometer. A substantially constant level of the sheath fluid is maintained. If the sheath fluid level falls below a desired level, or goes above a desired level, a dampened control system is used to reach the desired level. In addition, air pressure in the pressurized internal container is controlled so that an external sheath container can be removed and refilled with additional sheath fluid without stopping the sheath delivery system 100. Differences in pressure are detected by a droplet camera, which measures the droplet breakoff point to determine the pressure of the sheath fluid in the nozzle.

Abstract: Disclosed is a sheath delivery system that uses a continuous flow of sheath fluid into a pressurized internal reservoir that substantially matches the outflow of sheath fluid through the nozzle of a flow cytometer. A substantially constant level of the sheath fluid is maintained. If the sheath fluid level falls below a desired level, or goes above a desired level, a dampened control system is used to reach the desired level. In addition, air pressure in the pressurized internal container is controlled so that an external sheath container can be removed and refilled with additional sheath fluid without stopping the sheath delivery system 100. Differences in pressure are detected by a droplet camera, which measures the droplet breakoff point to determine the pressure of the sheath fluid in the nozzle.

Abstract: Methods and systems for pumping fluid through tubing are provided. Methods include orbiting one or more first rollers at multiple angular speeds around the periphery of a substantially circular first disk having a first radius with each first roller travelling at the same angular speed as the other first rollers, orbiting second rollers at a second angular speed around a substantially circular second disk having substantially the first radius, and increasing the pressure of fluid in tubing between one first roller and one second roller by causing the one or more first rollers to orbit at a first angular speed greater than the second angular speed so the one first roller moves along and fully compresses the tubing in a first section of the first disk, and simultaneously causing the one second roller to move along and fully compress the tubing in a first section of the second disk.

Abstract: Disclosed is a threshold selector that selects a threshold by generating a histogram from a detector signal and a flow cytometer. The detector signal includes both data and noise. A histogram is generated, which includes height data from the pulses of the detector signal as well as noise. The flow cytometer can be operated without samples to generate a histogram that includes only noise. The threshold signal can then be selected by selecting an intensity level on the histogram that is between the noise and data.

Abstract: Disclosed is a system that can mix deionized water and concentrated sheath fluid to provide sheath fluid in a flow cytometer system having a desired concentration. Flow rates are low, which substantially match the flow rate of sheath fluid through the nozzle, so that turbulence and air bubbles are not formed in the sheath fluid. The available deionized water is then used for back flushing and removal of sample cells and deposited salts from the sheath fluid.

Abstract: Disclosed is an automated method and apparatus for automatically setting a drop delay period by detecting calibration particles in a waste stream. The drop delay is incremented over a series of drop delays and the number of calibration particles in the waste stream is detected for each drop delay. The drop delay is selected which has the least number of calibration particles in the waste stream.

Abstract: Disclosed is a sheath delivery system that uses a continuous flow of sheath fluid into a pressurized internal reservoir that substantially matches the outflow of sheath fluid through the nozzle of a flow cytometer. A substantially constant level of the sheath fluid is maintained. If the sheath fluid level falls below a desired level, or goes above a desired level, a dampened control system is used to reach the desired level. In addition, air pressure in the pressurized internal container is controlled so that an external sheath container can be removed and refilled with additional sheath fluid without stopping the sheath delivery system 100. Differences in pressure are detected by a droplet camera, which measures the droplet breakoff point to determine the pressure of the sheath fluid in the nozzle.

Abstract: Disclosed is a system that can mix deionized water and concentrated sheath fluid to provide sheath fluid in a flow cytometer system having a desired concentration. Flow rates are low, which substantially match the flow rate of sheath fluid through the nozzle, so that turbulence and air bubbles are not formed in the sheath fluid. The available deionized water is then used for back flushing and removal of sample cells and deposited salts from the sheath fluid.

Abstract: Disclosed is a threshold selector that selects a threshold by generating a histogram from a detector signal and a flow cytometer. The detector signal includes both data and noise. A histogram is generated, which includes height data from the pulses of the detector signal as well as noise. The flow cytometer can be operated without samples to generate a histogram that includes only noise. The threshold signal can then be selected by selecting an intensity level on the histogram that is between the noise and data.

Abstract: A method and apparatus for pumping fluid through tubing are provided. The method includes orbiting first rollers around the periphery of a first disk at a first tangential speed in a first angular sector and a slower, second tangential speed in a second angular sector, orbiting second rollers around the periphery of a second disk at the second tangential speed, and increasing the pressure of fluid in tubing between one first roller and one second roller by causing the one first roller to fully compress the tubing at the first tangential speed and simultaneously causing the one second roller to fully compress the tubing at the second tangential speed. The apparatus includes a first disk with a recess in its periphery, the first angular sector with a nominal first radius, and a second angular sector with a nominal second radius; and a second disk with the nominal first radius and a recess in its periphery.

Abstract: Disclosed is a system and method for characterizing optical filters in a flow cytometer and optionally checking the operation of detectors in the flow cytometer. In some embodiments, the system may utilize an LED board having an opening through which the fluorescence and side scatter beams, rays, or images pass and light emitting diodes around the opening that emit light having different spectral profiles. The different spectral profiles allow the system to identify the optical filters that are placed in the flow cytometer, to verify detector operation, to assist in instrumentation troubleshooting, and to provide a quantitative reference for detector comparison.