# Measure fluorescence intensity at the nuclear envelope¶

This example reproduces a well-established workflow in bioimage data analysis for measuring the fluorescence intensity localized to the nuclear envelope, in a time sequence of cell images (each with two channels and two spatial dimensions) which shows a process of protein re-localization from the cytoplasmic area to the nuclear envelope. This biological application was first presented by Andrea Boni and collaborators in 1; it was used in a textbook by Kota Miura 2 as well as in other works (3, 4). In other words, we port this workflow from ImageJ Macro to Python with scikit-image.

1

Boni A, Politi AZ, Strnad P, Xiang W, Hossain MJ, Ellenberg J (2015) “Live imaging and modeling of inner nuclear membrane targeting reveals its molecular requirements in mammalian cells” J Cell Biol 209(5):705–720. ISSN: 0021-9525. DOI:10.1083/jcb.201409133

2

Miura K (2020) “Measurements of Intensity Dynamics at the Periphery of the Nucleus” in: Miura K, Sladoje N (eds) Bioimage Data Analysis Workflows. Learning Materials in Biosciences. Springer, Cham. DOI:10.1007/978-3-030-22386-1_2

3

4

Vorkel D and Haase R (2020) “GPU-accelerating ImageJ Macro image processing workflows using CLIJ” https://arxiv.org/abs/2008.11799

import matplotlib.pyplot as plt
import numpy as np
import plotly.io
import plotly.express as px
from scipy import ndimage as ndi

from skimage import (
filters, measure, morphology, segmentation
)
from skimage.data import protein_transport


image_sequence = protein_transport()

print(f'shape: {image_sequence.shape}')


Out:

shape: (15, 2, 180, 183)


The dataset is a 2D image stack with 15 frames (time points) and 2 channels.

fig = px.imshow(
image_sequence,
facet_col=1,
animation_frame=0,
labels={'animation_frame': 'time point', 'facet_col': 'channel'}
)
plotly.io.show(fig)