ISO 24479:2024

International
Standard
ISO 24479
First edition
Biotechnology — Cellular
2024-10
morphological analysis — General
requirements and considerations
for cell morphometry to quantify
cell morphological features
Biotechnologie — Analyse morphologique cellulaire — Exigences
générales et considérations pour la morphométrie cellulaire afin
de quantifier les caractéristiques morphologiques des cellules
Reference number
© ISO 2024
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ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations . 4
5 General Concept . 5
5.1 Cell morphometry .5
5.2 Steps for cell morphometry .5
6 Target of interest (TOI) . 5
7 Image capture . 6
7.1 Microscopic observation method . .6
7.1.1 General .6
7.1.2 Cell properties to be observed .7
7.1.3 Sample preparation .7
7.2 Microscope system and its settings .9
7.2.1 General .9
7.2.2 Light source .11
7.2.3 Objective lens and condenser lens .11
7.2.4 Components in optical path .11
7.2.5 Image capture device . 12
7.2.6 Image data . 12
7.2.7 Environmental conditions . 12
7.2.8 Observing position . 12
7.2.9 Image capturing conditions . 13
7.3 Execution of image capture . 13
7.3.1 Single image capture. 13
7.3.2 Multiple image capture . 13
8 Segmentation of the TOI .13
9 Quantification . 14
9.1 General .14
9.2 Procedure to quantify morphological features of segmented object .14
10 Qualification of Measurement . 14
11 Reporting .15
11.1 General . 15
11.2 Reporting of sample properties and sample preparation . 15
11.3 Reporting of the microscopic observation method . 15
11.4 Reporting of the image data, image pre-processing, and image analysis for
morphometric analysis .16
11.5 Reporting of the morphological features for morphometric analysis .17
Annex A (informative) Check sheet regarding selection of contrast-enhancing techniques for
optical microscopy .18
Annex B (informative) Check sheet regarding selection of microscope system .20
Annex C (informative) List of cell morphological descriptors, definitions and formulae for cell
shape, size .21
Annex D (informative) List of cell morphological descriptors, definitions and formulae for cell
texture .29

iii
Annex E (informative) Points to consider when acquiring phase-contrast images of cells
suitable for image analysis .34
Bibliography .43

iv
Foreword
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v
Introduction
Optical microscopy is a widely practiced technique for characterization of processed cells. Morphology of
cells, such as shape, size, texture of whole or parts of cells, can provide information about various aspects of
cells including identity, phenotype, viability, doubling time, as well as the states of stress and drug responses.
Morphological evaluation of cells is widely employed in basic research, drug discovery, in-process control
and release testing for cell manufacturing and cell banks for cell-based therapeutic products.
Therefore, it is desired to establish a common understanding of definitions and formulae regarding cell
morphological descriptors in which specialists in research and business fields can refer to and compare
information, within an institution, and with other interested parties.
The current situation is that characteristics of cell morphology obtained from microscopic images are
frequently described qualitatively in expressions such as "unevenness around", "elongated", "rounded". Even
when cell morphological descriptors characterizing the morphology of the cell are measured and quantified
from the cell image, these cell morphological descriptors are not consistently used.
This document allows to check whether the numerical values assigned as cell morphological descriptors are
calculated by an appropriate method, and to improve the reliability of the measured value and the evaluation
result. It is expected that the "common language of definitions and mathematical formulae" based on this
document will enable the accumulation of more reliable data, and such language will provide a basis for
assessment whether individually acquired data can be quantitatively compared to each other.
This document is intended primarily for users, both in academia and industry, who evaluate cell
characteristics. However, it can also be referred to by suppliers of tools such as microscopes, image
processing devices, and software, suppliers of database that handle information on cell morphology and
users who write scientific papers regarding cell morphology.

vi
International Standard ISO 24479:2024(en)
Biotechnology — Cellular morphological analysis — General
requirements and considerations for cell morphometry to
quantify cell morphological features
1 Scope
This document provides general requirements for cell morphometry to quantify cell morphological features
including cell shape, size and texture.
This document addresses aspects of cell image capture using optical microscopy and image processing for
morphometry.
This document does not address the statistics associated with a morphological analysis of a cellular sample.
This document also gives terms and definitions corresponding to cell morphological descriptors, and lists
examples and their formulae, that represent quantitative cellular morphological features for evaluation of
cell morphology in cell analysis.
This document primarily applies to morphological analysis of cultured mammalian cells.
This document is not intended for imaging used in clinical diagnostics.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
aberration
failure of an optical system to produce a perfect image
EXAMPLE Spherical aberration, chromatic aberration
[SOURCE: ISO 10934:2020, 3.1.4, modified — “objective lens aberration” removed a preferred term and
examples added.]
3.2
bit depth
maximum number of discrete levels available for the digitized representation of the signal intensity,
represented as a power of 2
[SOURCE: ISO 22493:2014, 5.2.2.2.1, modified — “colour depth” and “pixel depth” are deleted from the
preferred term, Notes 1 and 2 to entry are deleted.]

3.3
bounding box
rectangular region enclosing annotated object
Note 1 to entry: The major and minor axes of the rectangle are parallel to the edges of the images.
[SOURCE: ISO/IEC 30137-4:2021, modified — second sentence of Note 1 to entry deleted.]
3.4
cell morphology
form and structure of either the cell, subcellular components, or both
Note 1 to entry: In view of cell morphometry (3.6), cell morphology can be represented by a single or multiple cell
morphological descriptor(s) (3.5) associated with morphological feature(s) (3.15).
3.5
cell morphological descriptor
quantitative representation of cell morphology (3.4)
3.6
cell morphometry
process of measuring dimensional, shape, and structural characteristics of cells including analysis of derived
properties
Note 1 to entry: Steps for cell morphometry starts with determination of a purpose of the cell morphology analysis
and ends with analysis of quantified results for the intended purpose. By taking these steps, cell morphometry can
derive properties, e.g. phenotype such as immunosuppressive activity. See Table 1 for details.
3.7
cell shape
external geometric form of a cell
[SOURCE: ISO/TR 13014:2012 2.26, modified — term “shape” has been changed to “cell shape” and “particle”
has been changed to “cell”.]
3.8
cell texture
spatial arrangement of colours or intensities in an image associated with cellular characteristics
Note 1 to entry: The pattern can have a specific spatial scale or colour.
Note 2 to entry: The cell texture can result from a specific arrangement of sub-cellular components.
3.9
convex hull
smallest convex set containing a given geometric object
Note 1 to entry: “convex set” is a geometric set where any line segment connecting two points in the set lies entirely
within the set.
[SOURCE: ISO 19107:2019, 3.15, modified – Note 1 to entry replaced.]
3.10
depth of focus
axial depth of the space on both sides of the image within which the image appears acceptably sharp, while
the positions of the object plane and of the objective are maintained
[SOURCE: ISO 10934:2020, 3.1.37, modified — Note 1 to entry is deleted.]
3.11
formula
recipe for calculating a value
[SOURCE: ISO/IEC 29500-1:2016, 12.1.7, modified — the explanatory statement has been deleted.]

3.12
field of view
FOV
field which is observed by the microscope
Note 1 to entry: The full image frame of a digital imaging device corresponds to its field of view.
[SOURCE: ISO 13322-1:2014, 3.1.6, modified — the term “viewing” has been changed to “microscope”.]
3.13
image capture
image acquisition
process of creating a two-dimensional original image of an object
[SOURCE: ISO 21227-1:2003, 3.4]
3.14
measurement
process of experimentally obtaining one or more quantity values that can reasonably be attributed to a
quantity
[SOURCE: ISO/IEC GUIDE 99:2007, 2.1, modified — Notes to entry have been deleted.]
3.15
morphological feature(s)
shape, size, and texture of cellular components
3.16
numerical aperture
NA
number originally defined by Abbe for objectives and condensers, which is given by the expression n sin u,
where n is the refractive index of the medium between the lens and the object and u is half the angular
aperture of the lens
Note 1 to entry: Unless specified by “image-side”, the term refers to the object side.
[SOURCE: ISO 10934:2020, 3.1.10.4]
3.17
optical resolution
numerical measure of the image quality of an optical system
[SOURCE: ISO 8600-5:2020, 3.12]
3.18
pixel resolution
number of imaging pixels per unit distance of the detector
[SOURCE: ISO 15253:2021, 3.7, modified —hyphen between “pixel” and “resolution” was deleted.]
3.19
region of interest
ROI
parts of an image to which discrete observations are applied
Note 1 to entry: Region is selected by observer’s intended purpose.
[SOURCE: ISO 10934:2020, 3.2.28, modified — Note 1 to entry has been added.]

3.20
segmentation
partitioning images into distinct regions
Note 1 to entry: A distinct region is determined in attention of target of interest.
Note 2 to entry: The partitioning process includes filter application to the image.
Note 3 to entry: Segmentation can be of individual pixels. In such case, segmentation means partitioning pixels within
images into distinct groups.
3.21
spatial resolution
smallest separation between two details in the object for which they can be detected as being separate
under a given set of conditions
[SOURCE: ISO 15253:2021, 3.7, modified – “recognized” was replaced to “detected”.]
3.22
tile capture
capturing method to extend a field of view by recording a series of tile images with limited field size
Note 1 to entry: Tile images can be recorded by systematically changing the relative position between the sample and
the objective lens by mechanical drive.
Note 2 to entry: If tiles overlap, the tile images can be stitched to a larger overview image based on motor position or
tile image correlation.
3.23
time lapse capture
image-recording method, in which multiple images are captured at specific time interval
Note 1 to entry: time lapse capture can be used for tracing changes in cell states or activities (such as cell division,
fusion or phagocytosis of processed cells).
3.24
target of interest
TOI
part, region or both of cell(s) for morphological examinations defined by observer’s intended purpose
3.25
Z-stack capture
image-recording method, in which multiple images are captured in the direction of the optical axis at a
selected distance interval
Note 1 to entry: Z-stacks can be used to create a 3D image or for capturing objects in different optical focal planes.
4 Abbreviations
DIC differential interference contrast
FOV field of view
NA numerical aperture
TOI target of interest
ROI region of interest
5 General Concept
5.1 Cell morphometry
Cell morphology represents various features and states of cells, such as cell division and apoptosis,
depending on the life cycle of the cell and environmental factors such as media contents and culture vessel.
Cell morphometry can provide information on phenotype, viability, proliferation, stages of differentiation,
function, and other cell characteristics. In addition, time-lapse observation of cell morphology can
characterize dynamic properties of cells such as migration ability. It can also reflect a stimulatory response
in a living biological system, including dynamic measurements of cellular morphology as an indication of
[6]
toxicity in drug screening .
NOTE There are cases where acquiring 3D-images and time series images includes specific sample preparation
[7-9]
and device handling, which are not covered in this document .
5.2 Steps for cell morphometry
Table 1 describes the steps for cell morphometry.
Table 1 — Steps for cell morphometry
Step# Summary Relevant clause
Step-1 Determine purpose of the cell morphology analysis -
(out of scope)
Step-2 Define appropriate TOI(s) for the intended purpose 6
Step-3 Select observation methods and sample preparation according to the 7.1
TOI(s)
Step-4 Select or establish microscope system 7.2, 7.3
Step-5 Adjust settings of microscope system in order to acquire images 7.2, 7.3
Step-6 Perform segmentation (including pre/post image processing) of the TOI(s) 8
from acquired images
Step-7 Select appropriate cell morphological descriptors which characterize seg- 9, 10
mented TOI(s) and determine their numerical values
Step-8 Preparation of a report for results of morphometric analysis 11
Step-9 Analysis with quantified results for the intended purpose (out of scope)
6 Target of interest (TOI)
The TOI should be defined according to intended purpose of the morphology analysis.
The TOI should be defined before conducting the image capture step. This is important to select observation
methods, microscope components and image capture devices, and their settings. Imaging conditions can be
optimized by visual observation.
Images should not be optimized for human perception but for downstream image processing and analysis.
NOTE When the image capture conditions are determined by human perception, and when the image is checked
after capture, the brightness, capture position, focus, image resolution, and other conditions can vary, which makes it
difficult to analyse the image.
Figure 1 describes the relationship between FOV, TOI, and ROI.

a) Relationship between FOV, ROI, and TOI in a b) Relationship between FOV, ROI, and TOI in a
single image made of a single FOV tiled image made of 9 FOVs
Key
1 FOV
2 TOI
3 ROI
NOTE For the purpose of Figure 1, TOI is cell nucleus, and ROI is set to include TOIs.
Figure 1 — Relationship between FOV, TOI, and ROI
7 Image capture
7.1 Microscopic observation method
7.1.1 General
Optical microscopy is one of the most widely applied method for cell observation. Manual microscopy has
[10]
been used in the past but is currently replaced by digital imaging and use of information technology .
In order to observe cells, users should consider the contrast of their sample and select methods (and
microscope system) that support sufficient contrast and resolution for imaging.
A contrast-enhancing technique for optical microscopy should be selected so that the TOI can be visualized
in sufficient contrast for the intended purpose prior to initiating measurements. Contrast-enhancing
techniques that utilize difference in refractive indices, such as phase contrast or differential interference
can be used. Staining (labelling, dyeing) can also be used. In addition, a method combining transmitted light
observation and digital image processing can be used. Users should be aware that those techniques can
influence morphometric measurements.
A microscope system including its components should be selected so that the TOI can be visualized in
sufficient spatial and temporal resolution for the intended purpose.
NOTE 1 Understanding the dimension of the TOI helps the proper selection and settings for microscope system.
NOTE 2 Proper system and its adjustments of settings can be selected using predetermined reference materials for
visual observation, such as positive/negative control cells or cell images. The points to consider for the selection are
listed in 7.1.2. A summary is given in Table A.1.

NOTE 3 Points to consider when acquiring phase-contrast images of cells suitable for image analysis are described
in Annex E. Checklists for adherent cells that do not form colonies, adhesive cells that form colonies, and spheroids are
given in Tables E.1, E.2, and E.3, respectively.
The microscopic observation method shall be documented.
7.1.2 Cell properties to be observed
7.1.2.1 Adherence and suspension
Microscopic observation method should be selected while taking the cell culturing condition (e.g adherence,
floating, or suspension) into account.
Cells adhered to the vessel wall tend to form a thin layer(s). Forming of a thin layer(s) decreases contrast
of these cells. Therefore, appropriate contrast-enhancing techniques should be applied (see Table A.1).
Assuming a flat homogenous substrate/image field, change in the location of cells during observation has
little impact on the quality of the acquired image of these cells.
Since cells suspended in the culture medium can change their locations during the observation, the
observation techniques should be selected in consideration of the temporal resolution.
7.1.2.2 Stack and stratification
Layering, stratification, and three-dimensional (3D) structuring of cells can affect cell observation.
NOTE 1 Most transmission-type methods are not adequate for observation of deep 3D structures because the
illumination light is scattered, and less light is transmitted through the sample. Imaging with infrared light can reduce
the influence of scattered light.
NOTE 2 When single-layer or multi-layer cells have significant variations in cell-layer thickness and height, a "halo"
image effect appears around the cells. This effect lowers image quality in phase-contrast observation.
NOTE 3 For fluorescence-type measurements, light emitted from cell outside the imaging plane can reduce image
quality. This problem can be reduced using confocal microscopy or related techniques. It is important to be aware that
changing of microscope type can change performance characteristics/traceability.
7.1.2.3 Intracytoplasmic structures
Intracytoplasmic structures (such as pigments, granules, and vacuoles) can affect image capture.
Intracytoplasmic structures increase cell contrast, therefore cells with sufficient amount of intracytoplasmic
structures can be observed not only by phase-contrast, differential-interference methods but also by other
transmitted light methods such as a brightfield.
7.1.3 Sample preparation
7.1.3.1 Sample preparation - general
Cell cultures are affected by the surrounding environment e.g., ambient temperature, humidity, CO
concentration. Changes in those conditions can lead to morphological changes of the cells up to cell death, in
some cases. Therefore, care should be taken that the observation environment is equivalent to the culture
environment, and that the cells do not undergo morphological changes during observation.
In addition, since morphological features of the cell changes depending on cell density and passages during
culture, care should be taken to use experimental conditions which fit the intended purpose.
In the case when a portion of cells is taken out from the cell population and used for observation, it should
be considered depending on the intended purpose, whether that portion includes the cells to be observed
or whether that portion is representative of the whole cell population. The intended purpose should be
described.
In the case when a portion of cells is transferred from the cell population to other vessels, procedures,
materials such as type of vessels and pipetting devices, and reagents applied for the transfer should be
properly selected.
Methods that can be applied for the observation depend on whether the observed or image-acquired cells
are to be discarded, continued in culture for further observation, or used for other purposes.
Procedure and condition of sample preparation shall be documented.
7.1.3.2 Sample preparation for specific observation - Labelling, dyeing, and chemical treatments
7.1.3.2.1 General
Histochemical staining, fluorescent labelling, immunostaining, or other chemical treatments can contribute
to TOI determination. Therefore, appropriate reagents and absorption/excitation wavelength and microscope
components should be selected. Histochemical staining, fluorescent labelling, immunostaining, or other
chemical treatments can alter cell membrane and nuclear properties, as well as other cell characteristics. As a
result, the morphological characteristics of the treated cells can be different from those of untreated living cells.
If cells are to be used after microscopic observation, a processing method that minimally interferes with the
intended use shall be applied.
7.1.3.2.2 Cell fixation
When fixing cells using a chemical fixative, a method that preserves cellular structures of interest should be
applied.
NOTE Chemical treatments such as cell fixation can alter cell membrane and nucleus properties, as well as other
cell characteristics. As a result, morphological features of treated cells can differ from those of living, untreated cells.
Further guidance can be found in ISO 20166-4.
7.1.3.2.3 Fluorescent labelling or immunostaining
When applying a staining process, the intensity of staining should be sufficient to allow the signal to be
detected over background.
NOTE 1 The term “detection” in the above sentence includes detection by visual observation and that by using an
image capture device. There are cases where subvisible dyes, i.e. dyes that are not seen with visual observation, can be
detected by using image capture device.
NOTE 2 If the light intensity is increased as a countermeasure to the insufficient staining, autofluorescence or
phototoxicity can occur.
Non-specific staining can occur depending on the nature of the labelling or dyeing procedure, e.g.,
concentration of the reagents used.
Some types of staining also affect cell characteristics, making it impossible to continue culturing after
observation and imaging.
Elapsed time and culture environment can affect cell activity and sensitization during observation or cause
a photochemical change of the stained material.
Labels used for immunostaining or other fluorescent labelling shall be documented. This should include
their excitation and emission characteristics.
If there is an intention to continue the cell culture after cell staining, the effect of cell staining on the
culturability of the cells should be considered.
7.1.3.3 Observation vessels
The material and design of vessel applied for microscopy can affect the observation of cells.

In the case when same vessel is used both for cell culture and observation, its material and surface treatment
should be suitable for both purposes.
On the other hand, there are cases that culturing is performed applying vessels which are incompatible for
microscopy. When vessel is changed for observation in such cases, it is necessary to make sure that the state
and morphological features of the cells are not affected by transportation between the vessels.
NOTE 1 The observation vessel is sometimes referred to as the sample holder, where the sample holder is the device
(or sample carrier, container or vessel) on which the specimen was mounted, cultured, or adhered for microscopical
examination. It is typically flat and can be made of glass or plastic (e.g., microscope slides, petri dishes, and multi-well
[11,12]
plates) .
NOTE 2 Vessels made of polymeric material are often not appropriate for differential interference microscopy
because of birefringence.
A vessel whose thickness entering the optical path is less than the working distance should be used.
NOTE 3 Working distance, i.e., the distance from a front lens element of the objective to a target of interest when
the target of interest is in focus, depends on the optical design of the objective, such as magnification and NA.
7.1.3.4 Contamination
In the case when the cell sample is to be applied for subsequent culture after observation, measures should
be taken to avoid contamination with microorganisms during the entire process from sample extraction,
preparation, observation, and return to the culture environment.
In cases where cells cannot be automatically observed in the culture environment, it is recommended that a
sample be removed from the culture, if possible, to avoid contamination of cells that will continue to undergo
culturing.
7.2 Microscope system and its settings
7.2.1 General
Microscope system consists of light source, objective lens, image capture device, stage and a set of other
filters and mirrors. The configuration of the instrument depends on the specific purpose of observation.
[13]
NOTE 1 This document presupposes that the microscope system is maintained properly. For this, several
resources exist. For example, traceable microscopic rulers and calibrated graticules can be used to calibrate size
[4,14] [3,5]
measurements . Normalizations for non-uniformity of the field can be applied .
The spatial resolution of the image is determined by the combined optical resolution of the lens and the pixel
resolution of the image capture device. Captured image of the ROI needs sufficient spatial resolution. The
camera should have the pixel resolution necessary to achieve it.
NOTE 2 The optical resolution of the lenses depends on its NA. The camera resolution is determined by the size of
the pixel and magnification.
Points to consider for each component depend on specific microscopic observation method.
The points to consider when selecting a microscope system and its settings are given in 7.2.2 to 7.2.9. A
summary is given in Table B.1.

Key
1 mirror
2 light source
3 condenser lens
4 environment
5 stage
6 sample
7 objective lens
8 set of fluorescent filters
9 excitation filter
10 dichroic mirror
11 fluorescence filter
12 light source
13 image capture device
14 image storage device
Figure 2 — Example of microscope system
If the initially obtained image does not sufficiently differentiate or characterize features, one should consider
whether the microscope or system settings should be readjusted for increased image quality, the sample
preparation process is sufficient, or the approach is otherwise not fit for purpose.

7.2.2 Light source
Light source should have an appropriate wavelength range, depending on the choice of the observation
method and characteristics of the cell object(s). Light source should have sufficient intensity to obtain the
necessary contrast (Figure E.1).
NOTE The term “light intensity” is used as a general term for the strength of light. It can be used to express
absolute strength or relative strength of light. An appropriate unit needs to be used in order to express the strength of
a particular light.
In particular, for fluorescence observation, a light source which produces sufficient fluorescence intensity
should be selected in consideration of the following viewpoints;
a) wavelength range appropriate for the excitation of the fluorescent substance,
b) light intensity that provides sufficient excitation.
NOTE A narrow bandwidth of the target wavelength range can lead to insufficient excitation and cause low
fluorescence if the intensity of the light source is attenuated.
The light source should provide sufficient contrast in the captured ROI and be appropriately adjusted so that
phototoxicity and fading are not a problem for the cells.
The light source should be stable such that changes in cell morphological descriptor value(s) due to light
fluctuations are negligible.
The wavelength and intensity of the light source used in the observations can affect cell properties. As a
result, there are cases where the illuminated cells are not suitable for subsequent culture.
7.2.3 Objective lens and condenser lens
Optical resolution, depth of focus and aberrations of the objective and condenser lenses should be within
a particular range according to the purpose of the image capture. The appropriate NAs should be selected
according to the required resolution. In selecting an objective lens, the information on the surface of the
[1]
objective lens is helpful. Marking of objective lenses is described in ISO 8578 .
NOTE Optical resolution and aberrations are affected by material and thickness of the vessel entering the optical path.
In the case of an immersion type of objective lens, the refractive index of immersion liquid should be selected
according to its optical design.
Specifications of the objective lens and the condenser lens shall be documented.
7.2.4 Components in optical path
Optical components that form optical path of the microscope system should be compatible to the wavelength
of the light(s). The light means the illumination light and the light emitted from the cells.
NOTE 1 Other optical components include lens, mirrors and filters.
NOTE 2 Mismatch between the wavelength of light used and the properties of optical component causes decrease
in transmittance of light through optical components.
For fluorescence observation, optical components, e.g., excitation filter, dichroic mirror, and fluorescence
filter, should be selected so that the fluorescence light can be distinguished from the excitation light.
Specifications of used optical components shall be documented. The optical components can include but are
not limited to:
a) spectral characteristics of the excitation filter, fluorescence filter and dichroic mirror;
b) objective lens;
c) condenser characteristics (e.g. numerical aperture, use of phase contrast filters);
d) model of microscope stand;
e) image capture device.
NOTE 3 Application of optical components such as filters and dichroic mirror are utilized for the selection of
excitation light and the selective detection of fluorescence lights.
When observing simultaneously a TOI that has been labelled by multiple fluorescence dyes, the image
capture devices should be properly configured to detect each fluorescent signal separately.
7.2.5 Image capture device
Captured image needs sufficient spatial resolution. The image capture device should have the pixel resolution
necessary to achieve it.
The spatial resolution of the image shall be documented.
NOTE 1 The spatial resolution depends on a combination of optical resolution and pixel resolution.
The sensitivity and the dynamic range, of the image capture devices should be both considered to capture
the image of the TOI in sufficient contrast.
NOTE 2 The sensitivity of the image capture devices is affected by the wavelength profile of the incident light. Some
image capture devices use nonlinear sensitivity curves to increase dynamic range.
If the sensitivity of the image capture devices is insufficient, a higher intensity light source is needed. In
such a case, it can cause phototoxicity or a photochemical change.
7.2.6 Image data
Image data shall have sufficient pixel resolution and bit depth sufficient for intended segmentation of the
TOI. In the case when image data is compressed, attention should be taken to maintain sufficient data for
segmentation. Any image compression processes shall be documented.
Image data should be accompanied with the meta data (e.g., image size, pixel resolution, bit depth,
[14]
compression type, data format) to maintain reusability of the image. Additional details are given in
Clause 11.
7.2.7 Environmental conditions
During observation, it is necessary to minimize environmental change which can cause alternation in cell
functions. The factors that can affect cell functions include, bu
...