Information
Project
chemotaxis demo
Experiment
chemotaxis demo
Replicate
chemotaxis demo
Replicate ID
148
Errors
Settings
Assay
Chemotaxis
Plate
Custom
Cell line
un-defined
Culture medium
Substance
Evaluation interval
300 secs
Recording duration
0
Min track duration
300 secs
Movement threshold
2 µm
Time between images
300 secs
Microscopy resolution
1.2 pixel/µm
Completed on
Incubator environment:
Glossary
| Term | Unit of Measure | Definition |
| Tracks Directness | µm | Directness is a measure of the straightness of the cell track trajectory. It is calculated by comparing the Euclidean distance and the accumulated distance. A directness of 1.0 equals a straight-line migration. |
| Accumulated Distance | µm | Accumulated distance is the total distance covered by a cell whether it ran in circles or a straight line. |
| Accumulated Euclidean Distance | µm | The sum of all cells' Euclidean Distances in the well. |
| Euclidean Distance | µm/time unit | A vector of a cell track end position less the cell track start position. If a cell ends where it starts, its euclidean distance will be zero. |
| Cell Speed | µm/time unit | Speed is a change in distance divided by change in time. This requires a start and end time for the calculations. We define speed over Evaluation Interval. We define speed as a changing value over time. A cell may move fast then stop and rest. It may move in circles and end where it starts. So it may have a high speed but show no chemotaxis directionality because it ends where it starts. |
| Cell Velocity | µm/time unit | Velocity is change in distance divided by change in time where the distance is the Euclidean Distance and the time is the entire track duration. It is an indicator of chemotatic effect. |
| Center of Mass Displacement | µm | Center of Mass Displacement (CoM) is the average Euclidean Distance for the x and y axis - CoMx and CoMy correspondingly. This is a very consise indication of the average Direction and magnitude of the overall cell movement in a well or condition group. The CoM report polar chart shows the average direction and magnitude of center of mass displacement for cells in the well or condition group. The CoM bar chart shows the magnitude of the center of mass displacement average for all cells in the well or condition group. |
| CoM Displacement Magnitudes | µm | A scalar that represents the magnitude of the CoM displacements, not the direction. |
| Endpoint Tracking Chart | µm | ... |
| Evaluation Interval | time unit | Speed and accumulated distance are measured on time intervals. This time interval can be the same as the frame time, or, it can be set to a number greater than the frame time. The Frame time is an experiment setting provided by user. |
| Forward Migration Index | % | Indication of change in the center of mass (CoM) on the X and Y axes. It is the average of the difference in starting points and ending points of all cell tracks. The values are normalized by dividing the Accumulated Distance. This is useful to indicate which axes have the highest percentage of the total CoM displacement. If the chemical gradient is on the Y axis, then the FMIy should be greater to indicate chemotactic effect. |
| Mean Cell Speed Excluding Non-Moving | µm/time unit | Cell speed excluding non-moving cells. Non-moving cells are those that do not meet the thresholds set with Minimum Track Duration or Movement Threshold experiment settings. |
| Mean Cell Speed Including Non-Moving | µm/time unit | Cell speed including all cells. |
| Mean Cell Velocity Excluding Non-Moving | µm/time unit | Cell velocitiy excluding non-moving cells. Non-moving cells are those that do not meet the thresholds set with Minimum Track Duration or Movement Threshold experiment settings. |
| Mean Cell Velocity Including Non-Moving | µm/time unit | Cell velocity including all cells. |
| Mean Euclidean Distance | µm | The mean of all cells' Euclidean Distance in the well. |
| Mean Square Displacement | µm² |
This implementation of Mean Square Displacement has been borrowed from the study of the dynamics of molecules and here applied to the dynamics of cells.
The dynamics of molecules (cells) has them colliding and recolliding with each other, and observation of the trajectory
of any given molecule (cell) will find that it meanders erratically and randomly through the available volume.
Although there is no directed motion, a molecule (cell) will not remain indefinitely in the vicinity of its present position.
The question arises, "how far will a molecule (cell) travel in a given time interval?" This matter is relevant to transport
processes in the material, most notably (but not only) the rate of diffusion. The mean square displacement (msd) is a measure of the average distance a molecule (cell) travels. It is defined 
In this equation, ri(t)-ri(0) is the (vector) distance traveled by molecule (cell) i over some time interval of length t, and the squared magnitude of this vector is averaged (as indicated by the angle brackets) over many such time intervals. Often this quantity is averaged also over all molecules (cell) in the system, summing i from 1 to N and dividing by N. |
| Minimum Track Duration | time unit | Track must have a time duration greater or equal to this experiment setting to be accounted by Valid Tracks metric and to be considered a moving cell. This is an experiment setting provided by user. |
| Movement Threshold | µm | A cell must move more than this threshold to be considered as moving cell in any time interval. If the cell movement is less than this value in any time interval, cell movement will not be counted as the Cell Speed or Accumulated Distance. The value can be used to prevent noisy signals from stationary cells. This is an experiment setting provided by user. |
| Rayleigh test | Rayleigh test is a statistical test for the uniformity of a circular distribution of points (cell endpoints). With p < 0.05, the null hypothosis (uniformity) is rejected, indicating a chemotaxis effect. Like all statistical tests, this one strongly depends on the number of analyzed cells. | |
| Report Time Interval (RTI) | time unit | Dynamically calculated based on the experiment setting Time between images value and total experiment duration. Can be one of the following: minutes, seconds, hours, days. |
| Time Point | time unit | Moment in time based on setting RTI value. Starts from 0 which corresponds to the first image of the experiment recording. |
| Total Tracks | ea | The total number of tracks discovered through all time intervals. |
| Total Valid Tracks | ea | The total number of tracks discovered through all time intervals that meet the Minimum Track Duration requirement. |
| Track Length | µm | Track Length is sum of distance in each time inteval. |
| Tracks Ending In Interval | ea | The number of tracks lost at time interval. |
| Tracks In Interval | ea | The number of active cell tracks at the given time interval. If cells die or leave the field of view, this number will drop. If cells replicate or enter the field of view, this number will increase. Tracks can also be lost due to tracking errors. If this image quality is low (out of focus areas for example), this can lead to errors. If the user observes an excessive error rate, this should be reported to MetaVi Labs Support for making improvement. |
| Tracks Starting In Interval | ea | The number of new tracks obeserved in time interval. |
| Track Trajectory | Track path with a normalized origin. |
View Wells Comparison Results
Tabular Results, all wells:
| Well | Total tracks | Total valid tracks | Non-moving cells | Moving cells | Moving cells (%) |
| pos1 | 4347 | 4347 | 318 | 4029 | 92.68 |
| pos2 | 4871 | 4871 | 323 | 4548 | 93.37 |
Tabular Results, all wells:
| Well | Avg. speed, moving cells (µm/min) | Avg. speed (µm/min) | Avg. velocity, moving cells (µm/min) | Avg. velocity (µm/min) |
| pos1 | 0.68 | 0.68 | 0.20 | 0.18 |
| pos2 | 0.65 | 0.65 | 0.19 | 0.18 |
Tabular Results, all wells:
| Well | Accumulated distance (µm) | Mean accumulated distance (µm) | Euclidean distance (µm) | Mean Euclidean distance (µm) |
| pos1 | 1794608.36 | 412.84 | 305548.14 | 70.29 |
| pos2 | 2074603.21 | 425.91 | 355862.99 | 73.06 |
Tabular Results, all wells:
| Well | Directness | FMIx | FMIy | CoMx (µm) | CoMy (µm) | Rayleigh test |
| pos1 | 0.27 | 0.01 | 0.08 | 1.43 | 32.00 | 0.00 |
| pos2 | 0.28 | -0.02 | 0.01 | -9.89 | -1.34 | 0.00 |
View Individual Well Results
pos1
Well tracking video
Tracking data:
Total tracks
4347
FMIx
0.01
FMIy
0.08
CoMx
1.43 µm
CoMy
32.00 µm
Avg. speed, moving cells
0.68 µm/min
Avg. speed
0.68 µm/min
Avg. velocity, moving cells
0.20 µm/min
Avg. velocity
0.18 µm/min
Directness
0.27
Accumulated distance
1794608.36 µm
Euclidean distance
305548.14 µm
Rayleigh test
0.00
pos2
Well tracking video
Tracking data:
Total tracks
4871
FMIx
-0.02
FMIy
0.01
CoMx
-9.89 µm
CoMy
-1.34 µm
Avg. speed, moving cells
0.65 µm/min
Avg. speed
0.65 µm/min
Avg. velocity, moving cells
0.19 µm/min
Avg. velocity
0.18 µm/min
Directness
0.28
Accumulated distance
2074603.21 µm
Euclidean distance
355862.99 µm
Rayleigh test
0.00