Comparative genomic hybridization (CGH) is a molecular cytogenetic technique that allows detection of copy number variations between a test and reference DNA sample without cell culturing. CGH involves labeling and hybridizing test and reference DNA to normal metaphase chromosomes before visualizing differences in fluorescence to identify regions of gains or losses. While CGH was originally used for cancer research, it can also detect chromosomal abnormalities associated with genetic disorders and has improved resolution over traditional cytogenetic methods. The main limitations of CGH are its inability to detect structural aberrations without copy number changes and resolutions above 5-10 megabases.
Comparative genomic hybridization is a molecular cytogenetic method for analysing copy number variations (CNVs) relative to ploidy level in the DNA of a test sample compared to a reference sample, without the need for culturing cells
Fluorescent in situ hybridization (FISH) is a cytogenetic technique that can be used to detect and localize the presence or absence of specific DNA sequences on chromosomes.
Deciphering DNA sequences is essential for virtually all branches of biological research. With the
advent of capillary electrophoresis (CE)-based Sanger sequencing, scientists gained the ability to
elucidate genetic information from any given biological system. This technology has become widely
adopted in laboratories around the world, yet has always been hampered by inherent limitations in
throughput, scalability, speed, and resolution that often preclude scientists from obtaining the essential
information they need for their course of study. To overcome these barriers, an entirely new technology
was required—Next-Generation Sequencing (NGS), a fundamentally different approach to sequencing
that triggered numerous ground-breaking discoveries and ignited a revolution in genomic science.
Comparative genomic hybridization is a molecular cytogenetic method for analysing copy number variations (CNVs) relative to ploidy level in the DNA of a test sample compared to a reference sample, without the need for culturing cells
Fluorescent in situ hybridization (FISH) is a cytogenetic technique that can be used to detect and localize the presence or absence of specific DNA sequences on chromosomes.
Deciphering DNA sequences is essential for virtually all branches of biological research. With the
advent of capillary electrophoresis (CE)-based Sanger sequencing, scientists gained the ability to
elucidate genetic information from any given biological system. This technology has become widely
adopted in laboratories around the world, yet has always been hampered by inherent limitations in
throughput, scalability, speed, and resolution that often preclude scientists from obtaining the essential
information they need for their course of study. To overcome these barriers, an entirely new technology
was required—Next-Generation Sequencing (NGS), a fundamentally different approach to sequencing
that triggered numerous ground-breaking discoveries and ignited a revolution in genomic science.
A cytological technique to detect the nature of adjacent chromosomal regions by using different staining technique assisted with some pre treatment of metaphase chromosomes prepared on the slides
Molecular diagnosis of genetic disease ppt for studentsthirupathiSathya
DEFINITION:
Dna analysis can be used for the identification of carriers of hereditary disorders.
For prenatal diagnosis of serious genetic conditions yearly diagnosis before the onset of symptoms is done MOLECULAR DIAGNOSIS OF GENETIC DISEASE
CYSTIC FIBROSIS:
Cystic fibrosis is a genetic disease that affect mostly lungs and also the pancreas.
Screening test:
It is a complex process
Large number of genetic alterations have to be done.
For eg : It is the one of the most common lethal autosomal recessive disorder in Europe.
It is caused by mutations to cystic fibrosis transmembrane conductance regulator(CFTR) gene .
Screening individuals who may be at risk for cystic fibrosis for 500 different mutations is a daunting task.
Diagnosis test that screen for a large number of mutations of a single gene in one assay being developed.
SICKLE CELL ANEMIA:
It is a disorder where red blood cells become rigid and sticky and are shaped like “sickle”.
This irregularly shaped cells stucks in small blood vessels which can slow and block the blood flow and oxygen to all the parts of the body.
There’s no cure for sickle cell anemia.
Screening for sickle cell anemia:
SCA is a genetic disease that is the result of a single nucleotide change in the codon for the sixth aminoacid of the β- chain of the hemoglobin molecule.
The anemia is caused by the inability of the mutated hemoglobin to carry sufficient oxygen.
Target – probe hybridasation is done.
STS stands for sequence tagged site which is short DNA sequence, generally between 100 and 500 bp in length, that is easily recognizable and occurs only once in the chromosome or genome being studied.
SNP (Single Nucleotide Polymorphic), SNP mapping, SNP profile, SNP types, SNP analysis by gel electropherosis and by mass spectrometry, SNP effects, single strand conformation polymorphism, SNP advantages and disadvantages and application of SNP profile in drug choice
A micro-array is a tool for analyzing gene expression that consists of a small membrane or glass slide containing samples of many genes arranged in a regular pattern.
This was made by me while I was in Masters. I have made few animations. I hope it makes understanding better.
The content is made by searching through internet and referencing books. I do not claim any content in whole presentation except the animations made on the subject.
A cytological technique to detect the nature of adjacent chromosomal regions by using different staining technique assisted with some pre treatment of metaphase chromosomes prepared on the slides
Molecular diagnosis of genetic disease ppt for studentsthirupathiSathya
DEFINITION:
Dna analysis can be used for the identification of carriers of hereditary disorders.
For prenatal diagnosis of serious genetic conditions yearly diagnosis before the onset of symptoms is done MOLECULAR DIAGNOSIS OF GENETIC DISEASE
CYSTIC FIBROSIS:
Cystic fibrosis is a genetic disease that affect mostly lungs and also the pancreas.
Screening test:
It is a complex process
Large number of genetic alterations have to be done.
For eg : It is the one of the most common lethal autosomal recessive disorder in Europe.
It is caused by mutations to cystic fibrosis transmembrane conductance regulator(CFTR) gene .
Screening individuals who may be at risk for cystic fibrosis for 500 different mutations is a daunting task.
Diagnosis test that screen for a large number of mutations of a single gene in one assay being developed.
SICKLE CELL ANEMIA:
It is a disorder where red blood cells become rigid and sticky and are shaped like “sickle”.
This irregularly shaped cells stucks in small blood vessels which can slow and block the blood flow and oxygen to all the parts of the body.
There’s no cure for sickle cell anemia.
Screening for sickle cell anemia:
SCA is a genetic disease that is the result of a single nucleotide change in the codon for the sixth aminoacid of the β- chain of the hemoglobin molecule.
The anemia is caused by the inability of the mutated hemoglobin to carry sufficient oxygen.
Target – probe hybridasation is done.
STS stands for sequence tagged site which is short DNA sequence, generally between 100 and 500 bp in length, that is easily recognizable and occurs only once in the chromosome or genome being studied.
SNP (Single Nucleotide Polymorphic), SNP mapping, SNP profile, SNP types, SNP analysis by gel electropherosis and by mass spectrometry, SNP effects, single strand conformation polymorphism, SNP advantages and disadvantages and application of SNP profile in drug choice
A micro-array is a tool for analyzing gene expression that consists of a small membrane or glass slide containing samples of many genes arranged in a regular pattern.
This was made by me while I was in Masters. I have made few animations. I hope it makes understanding better.
The content is made by searching through internet and referencing books. I do not claim any content in whole presentation except the animations made on the subject.
Micro array based comparative genomic hybridisation -Dr Yogesh DDr.Yogesh D
This is a brief introduction to the technique and principle of Array Comparative Genomic Hybridization. Array CGH is a powerful tool for genetic testing and has been enormously useful in cancer cytogenetics, prenatal genetic testing etc.
Reproductive behaviour: 1-Sexual behaviour in animalsrhfayed
Reproductive Behaviour involve behaviour patterns associated with courtship, copulation, birth, maternal care and with suckling attempts of newborn. It is species specific behaviour
diagnosis of cancer, bioluminescent detection, diagnosis of cancer, haplotype mapping, imaging gene expression in vivo, types of cancer diagnosis method, ultrasound imaging
Liquid biopsy quality control – the importance of plasma quality, sample prep...Thermo Fisher Scientific
Liquid biopsy is emerging as a non-invasive companion to traditional solid tumor biopsies. As next generation sequencing (NGS) of circulating cell-free nucleic acids (cfNA = cfDNA and cfRNA) becomes common, it’s important to understand the impact of sample preparation on quality, specificity, and sensitivity of liquid biopsy tests. Plasma samples are often limited, and may have undesirable characteristics such as lipemia or hemolysis that contribute unwanted genomic DNA (gDNA) to the sample. Low cfDNA concentration can also limit the amount available for NGS library prep. In this study, we explore the effects of suboptimal plasma and low library input on liquid biopsy NGS, and discuss various techniques for in-process quality control of cfNA samples isolated from plasma
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
3. • CGH is a molecular cytogenetic method for analyzing
copy number variations (CNVs) relative to poidy level in
the DNA for a test sample compared to a reference
sample, without the need for culturing cells.
• The aim is to quickly and efficiently compare two
genomic DNA samples arising from two sources which
are mostly often closely related.
• This technique was originally developed for the
evaluation of the differences between the
chromosomal complements of solid tumor and normal
tissue, and has an improved resoIution of 5-10
megabases compared to the more traditional
cytogenetic analysis techniques of giemsa banding and
fluorescence in situ hybridization (FISH) which are
limited by the resolution of the microscope utilized
Introduction of CGH
4. Introduction of CGH
• In short, this involves the isolation of DNA from the two sources to be
compared, most commonly a test and reference source, independent
labelling of each DNA sample with a different fluorophores (fluorescent
molecules) of different colours (usually red and green), denaturation of the
DNA so that it is single stranded, and the hybridization of the two resultant
samples in a 1:1 ratio to a normal metaphase spread of chromosomes, to
which the labelled DNA samples will bind at their locus of origin.
• Using a fluorescence microscope and computer software, the differentially
coloured fluorescent signals are then compared along the length of each
chromosome. A higher intensity of the test sample colour in a specific
region of a chromosome indicates the gain of material of that region in the
corresponding source sample, while a higher intensity of the reference
sample colour indicates the loss of material in the test sample in that
specific region. A neutral colour (yellow when the fluorophore labels are red
and green) indicates no difference between the two samples in that
location
5. History:
The first report of CGH analysis was by Kallioniemi and
colleagues in 1992 at the University of california, San
Franscisco, who utilised CGH in the analysis of solid tumors.
Soon after 1993, du Manoiret al. reported vertually same
methodology. Applied CGH to genomic DNA from patients
affected with either Downs syndrome or T-cell
prolymphocytic leukemia as well as cells of a renal papillary
carcinoma cell line.
(It was concluded that the fluorescence ratios obtained were
accurate and that differences between genomic DNA from
different cell types were detectable, and therefore that CGH
was a highly useful cytogenetic analysis tool)
6. • Initially, the widespread use of CGH technology was
difficult, as protocols were not uniform.
• However, in 1994 a review was published which
described an easily understood protocol in detail and
the image analysis software was made available
commercially, which allowed CGH to be utilised all
around the world.
• As new techniques such as microdissection and
degenerate oligonucleotide primed polymerase chain
reaction (DOP-PCR) became available for the
generation of DNA products, it was possible to apply
the concept of CGH to smaller chromosomal
abnormalities, and thus the resolution of CGH was
improved.
7. Metaphase Slide Preparation
Isolation of DNA from Test Tissue and Reference
Tissue
DNA Labelling
Blocking
Hybridization
Fluorescence Visualisation and Imaging
Basic Methods
8. Metaphase Slide Preparation
The DNA on the slide is a reference sample, and is thus
obtained from a karyotypically normal man or woman
Isolation of DNA from Test Tissue and Reference
Tissue
Standard phenol extraction is used to obtain DNA from
test or reference (karyotypically normal individual) tissue
DNA Labelling
It is then important to check fragment lengths of both
test and reference DNA by gel electrophoresis, as they
should be within the range of 500kb-1500kb for
optimum hybridization
9. Blocking
Unlabelled Life Technologies Corporation's Cot-1 DNA®
(placental DNA enriched with repetitive sequences of length
50bp-100bp)is added to block normal repetitive DNA
sequences, particularly atcentromeres and telomeres, as if
these sequences are detected, they may reduce the
fluorescence ratio and cause gains or losses to escape
detection
Hybridization
8-12µl of each of labelled test and labelled reference DNA
are mixed and 40 µg Cot-1 DNA® is added, then precipitated
and subsequently dissolved in 6µl of hybridization mix, which
contains 50% formamide to decrease DNA melting
temperature and 10% dextran sulphate to increase the
effective probe concentration in a saline sodium citrate (SSC)
solution at a pH of 7.0
10. Fluorescence Visualisation and Imaging
Dedicated CGH software is commercially
available for the image processing step, and is
required to subtract background noise, remove
and segment materials not of chromosomal
origin, normalize the fluorescence ratio, carry out
interactive karyotyping and chromosome scaling
to standard length
11.
12.
13.
14. • The identification of chromosomal regions that are
recurrently lost or gained in tumors, as well as for
the diagnosis and prognosis of cancer. This
approach can also be used to study chromosomal
aberrations in fetal and neonatal genomes.
• Furthermore, conventional CGH can be used in
detecting chromosomal abnormalities and have
been shown to be efficient in diagnosing complex
abnormalities associated with human genetic
disorders.
Applications of CGH
15. • CGH in cancer research
– CGH data from several studies of the same tumor type
show consistent patterns of non-random genetic
aberrations.Some of these changes appear to be
common to various kinds of malignant tumors, while
others are more tumor specific.
• Chromosomal Aberrations
– Cri du Chat (CdC) is a syndrome caused by a partial
deletion of the short arm of chromosome 5.Several
studies have shown that conventional CGH is suitable to
detect the deletion, as well as more complex
chromosomal alterations.
16. • inability to detect structural chromosomal aberrations, without
copy number changes, such as mosaicism, balanced chromosomal
translocations, and inversions.
• CGH can also only detect gains and losses relative to the ploidy
level.
• The limited resolution of metaphase chromosomes, aberrations
smaller than 5–10 Mb cannot be detected using conventional
CGH.
• The main disadvantage of array CGH is its inability to detect
aberrations that do not result in copy number changes and is
limited in its ability to detect mosaicism.
Limitations of CGH
17. • Another disadvantage is the lack of commercial
availability of the arrays.
• However, array preparation still needs to be
performed by the investigators themselves.
Inconsistencies in visualization and imaging
software as well as interpretation parameters also
make it difficult for replications and comparisons to
be made by different laboratory teams
19. Array CGH applications are mainly directed at detecting genomic
abnormalities in cancer. However, array CGH is also suitable for the
analysis of DNA copy number aberrations that cause human genetic
disorder. That is, array CGH is employed to uncover deletions,
amplifications, breakpoints and ploidy abnormalities. Earlier
diagnosis is of benefit to the patient as they may undergo
appropriate treatments and counseling to improve their prognosis
Genomic abnormalities in cancer
Submicroscopic aberrations
Prenatal Genetic Diagnosis
Array CGH
