1High throughput dynamic light scattering instrumentPre-operation preparation
Environmental Requirements
Choose a stable, dry, and temperature suitable location to install the instrument, ensuring that the bottom of the instrument is in smooth contact with the ground, the light path is perpendicular to the ground, and the bottom of the instrument is at least 50cm above the ground.
Avoid air flow, vibration, and strong electromagnetic interference sources (such as large motors and high-frequency equipment) to ensure a stable measurement environment.
sample preparation
Dispersion: The sample should be evenly dispersed in a liquid medium to avoid aggregation or precipitation. The dispersant needs to be transparent, have a refractive index different from that of solute particles, clean, and can be filtered.
Concentration control:
Protein samples: The recommended concentration for 14kDa protein is 1mg/ml, and the recommended concentration for 28kDa protein is 0.5mg/ml.
Other samples: Adjust the concentration according to the particle size to avoid multiple light scattering (high concentration) or weak signal (low concentration).
Remove bubbles: The sample needs to be centrifuged at 12000rpm for 10 minutes, and the supernatant should be taken to avoid bubbles affecting the measurement.
Sample size: The sample pool has a capacity of approximately 14 μ l. It is recommended to prepare 20 μ l of sample to ensure full filling.
Instrument inspection
Check if the power supply, connecting wires, and optical system are functioning properly, ensuring that components such as the laser, detector, and temperature control module are securely connected.
Preheat the instrument for 10-15 minutes and measure after the system stabilizes.
2、 Startup and software connection
Power-on procedure
Connect the power supply and turn on the host, temperature control module, and computer power in sequence.
Run measurement software (such as Zetasizer, IRSoft, etc.), click "Connect" or "Hardware" to establish a connection between the software and the instrument, confirm the successful connection, and the icon will turn green.
Parameter Settings
Laser intensity: Adjust according to sample concentration (high concentration samples need to reduce power to avoid signal overload).
Temperature: Set the measurement temperature (such as 25 ℃) and maintain a constant temperature for 120 seconds to stabilize the sample temperature.
Solvent parameters: Enter the refractive index (RI) and viscosity of the solvent, which need to be updated in real-time as the temperature changes.
Sample parameters: Enter the refractive index (RI) and absorption index (Absorption) of the sample. For protein samples, select the "Material" type and enter the corresponding parameters.
Measurement time: Set according to the stability of the sample (such as measuring continuously for 3 times, each time for 120 seconds).
Scattering angle: Usually 90 ° (for small particles) or 173 ° (for large particles) is selected.
Data filtering: Set the deviation range (such as Baseline=1 ± 0.003) to filter out abnormal data.
3、 Sample placement and measurement
Sample pool cleaning
Rinse the micropipette and sample tank with water to avoid contamination.
Slowly inject the sample into the sample cell using a micro pipette, avoiding scratching the bottom or side walls of the cell with the needle.
Place the sample pool into the sample chamber, ensuring that the arrow is facing towards you, and cover the sample chamber lid.
data collection
Click "Start" or "Measure" to start measuring, and the instrument automatically records the changes in scattered light intensity over time.
Avoid touching the instrument or sample cell during the measurement process to prevent optical path deviation.
The red data represents values that exceed the set range and are not used for analysis.
4、 Data analysis and storage
particle size distribution
The software automatically calculates the hydrodynamic radius (Rh) and polydispersity index (PDI), and generates particle size distribution maps (such as log normal distribution and MSD multisize distribution).
Correlation function
Analyze the relationship between light intensity fluctuations and time, and evaluate sample uniformity.
Data export
Save in CSV, Excel, or PDF format for further processing or report generation.
5、 Post operation maintenance
Sample pool cleaning
After the measurement is completed, immediately rinse the sample tank with water, blow dry it, and store it to avoid residual sample contamination.
Cleaning of optical components
Regularly clean optical components (such as laser windows and detectors) using dust-free cloths or specialized cleaning agents.
Instrument inspection
Check if there are any debris or dust inside the instrument, and keep the dry tube of the optical path system in a moisture absorbing state (if moisture is absorbed, it needs to be dried and regenerated).
Regularly use standard particles (such as polystyrene latex) for calibration to ensure measurement accuracy.
storage environment
When the instrument is not in use, store it in a dry, ventilated, and non corrosive gas environment, disconnect the power supply, and cover it with a dust cover.
Avoid contact with hazardous chemicals to prevent safety accidents.
VIHigh throughput dynamic light scattering instrumentCommon problem handling
Excessive light scattering intensity
Phenomenon: The instrument shows a self-protection prompt.
Reason: The sample concentration is too high or the particle size is too large.
Solution: Reduce sample concentration or adjust laser intensity.
Poor data uniformity
Phenomenon: The correlation function fluctuates greatly.
Reason: The sample is uneven or contains large particles.
Solution: Centrifuge the sample again to ensure even dispersion.
Optical path offset
Phenomenon: Abnormal measurement data.
Reason: Touching the instrument or sample pool during operation.
Solution: Adjust the light path again to ensure the vertical and parallel relationship between the light path, object, and detector.