Chromosome painting is a technique that uses fluorescent in-situ hybridization (FISH) to identify human chromosomes. It involves hybridizing a labeled DNA probe to a target DNA sequence within a cell nucleus. Different types of probes like centromeric, telomeric, whole chromosome, and locus-specific can be used with multiple colors to detect single or multiple genetic events within a cell without destroying its morphology. The procedure involves preparing samples on slides, using probes labeled with fluorescent molecules, and visualizing the signals under a fluorescence microscope equipped with appropriate filters. Chromosome painting has applications in locating genes, detecting translocations and abnormalities, and prenatal genetic disorder diagnosis.

1. INDIAN INSTITUTE OF TECHNOLOGY ROORKEE
CHROMOSOME PAINTING: A METHOD FOR
CELL CHARACTERIZATION
Presented by:
Prince
Ph.D. Scholar
Enroll. no. 18903011
Department of Biotechnology
Indian Institute of Technology, Roorkee

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INTRODUCTION

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WHY??????

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Fluorescent In-Situ Hybridization (FISH) identification of Human
Chromosomes - "Chromosome Painting"

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• A technique that hybridizes a DNA nucleic acid probe
to a target DNA sequence contained within a cell
nucleus.
• A variety of specimen types can by analyzed using
FISH. The intact cells are attached to a microscope
slide using standard cytogenetic methods.
FISH

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Probes
• Probe is a nucleic acid that
–can be labeled with a marker which
allows identification and quantitation.
–will hybridize to another nucleic acid on
the basis of base complementarity.

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Probes
Types of labeling
• Direct & Indirect
• Radioactive (32P, 35S, 14C, 3H)
• Fluorescent
Biotin, fluorescein, Digoxigenin etc.

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FISH for Detection of Single to Multiple
Genetic Events
Single Target
One color
Dual Targets
Two colors
Multiple
Targets
Multi- colors
Allows one to look at multiple genomic changes within a
single cell, without destruction of the cellular morphology.

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PROCEDURE FOR SAMPLE PREPARATION

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Types of FISH Probes
• Centromere
• Telomere
• Whole chromosome paint
• locus

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Types of probes
Centromeric (satellite)
probes
Locus specific probes
Whole chromosome painting probes

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Visualization of the Probe
• DNA probe is labeled with a colored fluorescent
molecule.
• This fluorescent molecule remains attached to the
DNA during the hybridization process
• The molecule emits a particular color when viewed
through a fluorescence microscope that is equipped
with the appropriate filter sets.

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Fluorescent Microscope
CCD Camera
Filters
FISH Analysis
Software

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APPLICATION
 To find out the location of a specific gene located on a
specific chromosome.
Detection of translocation.
Detection of chromosome abnormalities.
To find out the chromosomal similarity between
divergent species.
Prenatal genetic disorder diagnosis.

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Thanks.