FISH FLOURESCENT IN-SITU HYBRIDIZATION

NARENDRA YADAV PAPER 3 UNIT 2

INTRODUCTION

FISH is a cytogenetic technique that uses fluorescent probes that bind to only those parts of the chormosomes with a high degree of sequences complementarity.

Fluorescent probe-DNA complex can be studied under fluroscent microscope.

Developed by the biomedical researchers in early’ 1980s.

Protocol Outline

Preparation of the fluorescent probes

Denaturation of the probe and the target

Hybridization of the probe and the target

Detection

DENATURE OF DNA

DENATURE OF PROBE

LABELLING WITH PROBE

HYBRIZATION OF DNA-PROBE

DETECTION

Flourescent labled organism

MicroRNA(green) and mRNA(red) visualization in differentiating C1C12 cells

Probes

Complementary sequences of target nucleic acids

Designed against the sequence of interest.

Probes are tagged with fluorescent dyes like biotin, fluorescein, Digoxigenin

Size ranges from 20-40 bp tO1000bp.

PROBES

Stellaris(R) RNA FISH probes.

Fiber FISH.

Q-FISH.

Flow-FISH.

APPLICATION

Use to detect and localize the presence and absence of the specific DNA sequences on chormosomes.

FISH often used for finding specific features in DNA for use in genetic counselling, medicine, and species identification.

FISH can also be used to detect and localize specific RNA target (mRNA, IncRNA, miRNA) in cells.

Also used to detect circulating tumor cells, and tissues samples.

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Diseases that are diagnosed using FISH include Angelman syndrome, 22q13 deletion syndrome,, acute lymphoblastic leukemia, Cri-du-chat, and Down syndrome.

FISH can also be used to compare the genomes of two biological species, to deduce evolutionary relationships.

BIBLIOGRAPHY

GOOGLE-IMAGES

WIKIPEDIA

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