1.0.1 Wound Healing (Scratch) Assay

 

Application Name

Wound Healing (Scratch) Assay

Version

1.0.1

Documentation Version

04.08.2021 - 1

Input Image(s)

2D (standard and/or WSI) / Time Series / z-Stack / Multichannel Images; RGB or Grayscale (8 bit)

Input Parameter(s)

Regions of interest (optional)

Keywords

wound, healing, scratch, in-vitro, directional cell migration, migration rate, regeneration, proliferation, growth, microscopy

Short Description

Detection and measurement of an (artificial) gap, the “scratch”, on a confluent cell monolayer for in-vitro wound healing research.

References / Literature

For more information regarding the assay check e.g. https://pubmed.ncbi.nlm.nih.gov/15576902/ or https://www.nature.com/articles/nprot.2007.30

Table of contents

IKOSA Prisma Wound Healing (Scratch) Assay

You can use this image analysis application or any of our other applications in your account on the IKOSA platform. If it is not on the list of available applications, please contact your organization's administrator or our team at support@kmlvision.com.

Application description

This application automatically measures the (artificial) gap, the so-called “scratch”, in images showing a cell monolayer. In addition to the scratch width, areas that are (not) covered with cells are quantified (including/excluding single cells or cell-free areas). The application supports images from phase contrast and brightfield microscopy and arbitrary cell types. This analysis can also be performed on time lapse recordings (time series) uploaded as 8-bit multipage TIFF files to study directional cell migration in vitro, z-stacks, or multichannel images, uploaded as 8-bit multipage TIFF files.

In the following sections, we provide the necessary input data requirements that are necessary to obtain accurate image analysis results and a description of the output files.

Input data requirements

Input image(s)

Input for this application is the following image data:

Image type

Color channels

Color depth (per channel)

Size (px)

Resolution (μm/px)

Image type

Color channels

Color depth (per channel)

Size (px)

Resolution (μm/px)

2D (standard and/or WSI),

Time Series,

Multichannel,

Z-Stack*

 

Check image formats

https://kmlvision.atlassian.net/wiki/spaces/KB/pages/3406725124

3 (RGB)

or

1 (Gray)

8 Bit

Standard images and WSI formats:

Min: 10 x 10
Max: 6144 x 6144

typically: 0.3-1.16

Image content

Microscopy (phase contrast or brightfield) image of a cell monolayer showing an (artificial) gap with no cells, typically taken with 10x magnification.

Additional requirements

  • The measurement of scratch width is only supported for images showing a single (not multiple) scratch.

Examples:

*Please note: Z-stack images cannot be uploaded into IKOSA but still can be analyzed via IKOSA Prisma API.

Important:

For all images, the following requirements apply:

  • The illumination must be constant throughout the image(s).

  • The sample must be in focus, i.e. no blurry regions in image(s).

Input parameter(s)

No additional input parameters are required for this application.

As an optional parameter, a single or multiple regions of interest (ROIs) can be defined in which the analysis should be performed (‘inclusion ROIs’).

Description of output files and their content

Files

File format

Description

File format

Description

1

csv

results.csv:

A csv file containing the analysis results for the input image or all inclusion ROIs.

2

jpg

results_vis/vis.jpg (2D image, no ROI), or

results_vis/t<time-step>_z<z-layer>_c<channel>.jpg (for time series, z-stack, or multichannel image, no ROI), or

results_vis/<roi-id>.jpg (2D image, ROI <roi-id>), or

results_vis/t<time-step>_z<z-layer>_c<channel>_<roi-id>.jpg (for time series, z-stack, or multichannel image, ROI <roi-id>):

A visualization of the analysis result for a specific time step (of a time series), z-layer (of a z-stack), or channel (of a multichannel image) for either the whole image (if no inclusion ROIs selected for analysis) or each individual inclusion ROI.

Description of visualizations:

  • Areas and contours

    • no color: scratch area (the largest uncovered area)

    • green: cells and cell-covered area

    • red: bubbles (=cell-free areas outside the scratch)

    • cyan: free/floating cells and cell aggregates inside of scratch

  • Lines

    • magenta: linear fit to scratch “frontlines”, only calculated when the cell-covered area borders are not yet touching anywhere and if the borders are not too curvy

3

json

roiMeta.json:

A json file containing all information regarding the ROIs defined for the analysis job to ensure reproducibility. The file is empty if no ROIs were defined for analysis.

4

jpg

rois_visualization.jpg, or

t<time-step>_z<z-layer>_c<channel>_rois_visualization.jpg:

An overview visualization to show locations of all analyzed ROIs for the 2D image or time step <time-step> of a time series, z-layer <z-layer> of a z-stack, or channel <channel> of a multichannel image.

Please note: This file is only created if inclusion ROIs were defined for analysis.

5

json

jobResultBundleMeta.json: A json file containing all information regarding the analysis job (application name and version, project, etc.) to ensure reproducibility.

Content

results.csv

Single csv-file

If one or more time steps (of a time series), z-layers (of a z-stack), or channels (of a multichannel image) were specified, the results in a specific row refer to the time step/z-layer/channel specified in the corresponding column.

If one or more ROIs were specified, the results in a specific row refer to the ROI specified in the corresponding columns, otherwise (empty ROI columns) the results refer to the whole image.

Column NO.

Column name

Examples

Value range

Description

Column NO.

Column name

Examples

Value range

Description

Col. no.

Column name

Examples

Value range

Description

1

t

3

1 - 

Time step, i.e. the position of the image in the time series.

2

z

5

1 - 

z-layer, i.e. the position of the layer in the z-stack.

3

c

2

1 - 

Channel, i.e. the position of the channel in the multichannel image.

4

roi_id

ROI-03

ROI-01 - 

<roi-id> starting from “ROI-01”. Empty, if no inclusion ROI is specified and the whole image was analyzed.

5

roi_name

“central”

text

Custom text to identify the ROI. Empty, if no inclusion ROI is specified and the whole image was analyzed.

6

total_area_without_scratch [Px^2]

1011878

0 - #of pixels in image

Total area without scratch in Pixel^2, includes cell-covered area, free/floating cells and bubbles (= cell-free areas outside the scratch).

7

total_area_without_scratch_ratio [%]

68.6

0 - 100

Ratio of total area without scratch to the total area of the image.

8

scratch_area [Px^2]

36698

0 - #of pixels in image

Total scratch area (cell-free area in center of image) in Pixel^2. Free/Floating cells inside of scratch are not considered part of the scratch.

9

scratch_area_ratio [%]

31.4

0 - 100

Ratio of scratch area to total area of image. Free/Floating cells inside of scratch are not considered part of the scratch.

10

scratch_area_incl_free_cells [Px^2]

37580

0 - #of pixels in image

Total scratch area (cell-free area in center of image) in Pixel^2. Free/Floating cells inside of scratch are considered part of the scratch.

11

scratch_area_incl_free_cells_ratio [%]

31.6

0 - 100

Ratio of scratch area to total area of image. Free/Floating cells inside of scratch are considered part of the scratch..

12

scratch_width_area [Px]

400.5

>=0

Scratch width in Pixel, calculated by dividing the scratch_area by the “total length” of the scratch, i.e. the maximum distance between two points on the scratch border. Maximum value depends on the scratch orientation.

13

scratch_width_frontlines_mean [Px]

435

>=0 

Scratch width in Pixel, estimated by mean distance between the two linearly fitted “frontlines” (scratch borders).Value is 0, if no frontlines have been fitted. Maximum value depends on the scratch orientation.

14

scratch_width_frontlines_min [Px]

430

>=0

Scratch width in Pixel, estimated by minimum distance between the two linear fitted “frontlines” (scratch borders).Value is 0, if no frontlines have been fitted. Maximum value depends on the scratch orientation.

15

scratch_width_frontlines_max [Px]

440

>=0

Scratch width in Pixel, estimated by maximum distance between the two linear fitted “frontlines” (scratch borders). 

Value 0, if no frontlines have been fitted. Maximum value depends on the scratch orientation.

16

is_scratch_closed

0

0 or 1

Boolean indicator if scratch is closed (1) or not (0).

17

cells_covered_area [Px^2]

22143

0 - #of pixels in image

Total area of cell-covered region in Pixel^2. Bubbles (= cell-free areas outside the scratch) are not included in this area.

18

cells_covered_area_ratio [%]

68.6

0 - 100

Ratio of cell-covered area to total area of image. Bubbles (= cell-free areas outside the scratch) are not included in this area.

19

cells_covered_area_incl_bubbles [Px^2]

23053

0 - #of pixels in image

Total area of cell-covered region in Pixel^2. Bubbles (= cell-free areas outside the scratch) are included in this area.

20

cells_covered_area_incl_bubbles_ratio [%]

68.9

0 - 100

Ratio of cell-covered area to total area of image. Bubbles (= cell-free areas outside the scratch) are included in this area.

Error information

More information about errors can be found in the Application Error Documentation.

Contact

If you have any questions about this app, as well as suggestions or ideas for new ones, email us at support@kmlvision.com.

Feel free to book a 30-minute meeting to speak with us about IKOSA and the apps!

https://calendly.com/kmlvision/book-the-ikosa-platform-demo

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