SlideShare a Scribd company logo
1 of 29
Download to read offline
SANIL VARGHESE
CORDOCENTESIS
FETOSCOPY
TRIPLE TEST
PRE-IMPLANTATION GENETIC
DIAGNOSIS
   POLAR BODY BIOPSY
   BLASTOMERE BIOPSY

KARYOTYPING
GENE MAPPING
Cordocentesis, also sometimes called
Percutaneous Umbilical Cord Blood
Sampling (PUBS), is a diagnostic
test that examines blood from the
fetus to detect fetal abnormalities.
Cordocentesis is performed
after 17 weeks of pregnancy.
An advanced imaging ultrasound
determines the location where the
umbilical cord inserts into the
placenta. The ultrasound guides a
thin needle through the abdomen
and uterine walls to the umbilical
cord. The needle is inserted into
the umbilical cord to retrieve a
small sample of fetal blood.
CORDOCENTESIS
PURPOSE
To Help In Diagnosis Of:
  Malformations of the fetus.
  Fetal infection (i.e. toxoplasmosis or
  rubella)
  Fetal platelet count in the maternal
  circulation.
  Fetal anemia.
  Isoimmunisation.
COMPLICATION
Blood loss from the puncture site
Infection
Drop in fetal heart rate
Premature rupture of membranes
Fever
Chills
Leaking of amniotic fluid
Fetoscopy is an endoscopic
procedure during pregnancy to allow
access to the fetus, the amniotic
cavity, the umbilical cord, and the
fetal side of the placenta.
It is done during & after 18
weeks of pregnancy
PROCEDURE
A small (3–4 mm) incision is made in the
abdomen, and an fetoscope is inserted
through the abdominal wall and uterus into
the amniotic cavity. Fetoscopy allows
medical interventions such as a biopsy or a
laser occlusion of abnormal blood vessels.
FETOSCOPY
PURPOSE
Evaluate the fetus for birth defects, such
as spina bifida as well as other defects
which can only be confirmed by a
Fetoscopy.
To collect samples of blood from the
umbilical cord, e.g. hemophilia or sickle
cell anemia.
Collect samples of skin tissue from the
fetus. The tissue can be tested for some
COMPLICATIONS
 Miscarriage, as high as 12%.
 Excessive bleeding, infection, or
 excessive leakage of the amniotic
 fluid.
 Preterm rupture of the membranes.
 Mixing mother’s blood with baby’s
 blood.
Also called as “Triple screen“, the “Kettering
  test”, the “Bart's test” or "Multiples of the
                Median (MoM)“.
3 tests:
• Maternal Serum Alpha-fetoprotein
  (MSAFP)
• Unconjugated estriol
• Human chorionic gonadotropin (hCG)
The triple test is an investigation
performed during pregnancy in the
second trimester (15-18 weeks) to classify
a patient as either high-risk or low-risk for
chromosomal abnormalities (and neural
tube defects).
 The triple screen test involves drawing
blood from the mother. The blood sample
is then sent to the laboratory for testing.
AFP is is produced in the yolk sac and fetal
liver.
INCREASED    MSAFP    UE3      hCG
  RISK OF
 DOWN’S       ↓        ↓        ↑
SYNDROME
TRISOMY 18    ↓        ↓        ↓
   NTD’s      ↑      NORMAL   NORMAL
  MOLAR       ↓        ↓       ++↑
PREGNANCY
 MULTIPLE     ↑      NORMAL     ↑
 GESTATION
PRE-IMPLANTATION GENETIC
DIAGNOSIS / EMBRYO SCREENING
As PGD can be performed on cells from
different developmental stages, the biopsy
procedures vary accordingly. Theoretically, the
biopsy can be performed at all preimplantation
stages, but only three have been suggested: on
unfertilised and fertilised oocytes (for polar
bodies, PBs), on day three cleavage-stage
embryos (for blastomeres) and on blastocysts
(for trophectoderm cells).
ADVANTAGES

 Helps prevents birth of children with
 chromosomal anomalies and single
 gene disorders.

 Eugenics.
POLAR BODY BIOPSY
The first and second polar body of the
oocyte are extruded at the time of the
conclusion of the meiotic
division, normally the first polar body is
noted after ovulation, and the second
polar body after fertilization.
By analyzing polar bodies it is
possible to study maternal genetic
makeup.
The disadvantage of polar body
biopsy is that, it detect paternally
derived chromosomal disorders &
single gene disorders (autosomal
dominant disorders, autosomal
recessive disorders and sex-linked
disorders).
BLASTOMERE BIOPSY
It is also called Embryo biopsy, Cleavage-
stage biopsy.
Cleavage-stage biopsy is generally performed
the morning of day three post-
fertilization, when normally developing
embryos reach the eight-cell stage.
A hole is made in the zona pellucida and one
or two blastomeres containing a nucleus are
gently aspirated or extruded through the
opening.
ADVANTAGE
The genetic input of both parents can be studied.
Karyotyping
It is the procedure by which the chromosomes are
arranged based on the sizes, position of the
centromere & pattern of the chromosome binding
• The test can be performed on a sample of
  blood, bone marrow, amniotic fluid, or tissue
  from the placenta.The sample is placed into a
  special dish and allowed to grow in the
  laboratory. Cells are later taken from the
  growing sample and stained. The laboratory
  specialist uses a microscope to examine the
  size, shape, and number of chromosomes in the
  cell sample.
The stained sample is
  photographed to
  provide a karyotype,
  which shows the
  arrangement of the
  chromosomes.
 Certain abnormalities
  can be identified
  through the number or
  arrangement of the
  chromosomes.
Chromosomes contain
  thousands of genes
  that are stored in
  DNA, the basic
  genetic material.
GENE MAPPING
Gene mapping, also called genome
mapping, is the creation of a genetic
map assigning DNA fragments to
chromosomes.
TYPES
1. Genetic mapping:- The relative position
   between 2 genes of a chromosome are
   determined using linkage analysis.
2. Physical mapping:- Using techniques like
   FISH technique, it is possible to determine
   the absolute position of a gene on a
   chromosome.
Fluorescent In Situ Hybridization (FISH)

 FISH is the most commonly applied method to
 determine the chromosomal constitution of an
 embryo. In contrast to karyotyping, it can be used
 on interphase chromosomes, so that it can be
 used on PBs & blastomeres.
 The cells are fixated on glass microscope slides
 and hybridized with DNA probes. Each of these
 probes are specific for part of a
 chromosome, and are labelled with a
 fluorochrome.
The use of probes for chromosomes X, Y, 13,
14, 15, 16, 18, 21 and 22 has the potential of
detecting 70% of the aneuploidies found in
spontaneous abortions.

In order to be able to analyse more
chromosomes on the same sample, up to
three consecutive rounds of FISH can be
carried out.
Cordocentesis, Fetoscopy, Triple Test, PGD Diagnostic Tests

More Related Content

What's hot

Genetic counselling & Prenatal Diagnosis
Genetic counselling & Prenatal Diagnosis Genetic counselling & Prenatal Diagnosis
Genetic counselling & Prenatal Diagnosis DrDilip86
 
Prenatal diagnosis
Prenatal diagnosisPrenatal diagnosis
Prenatal diagnosisobgymgmcri
 
Amniocentesis
AmniocentesisAmniocentesis
Amniocentesislabuckley
 
Invasive & non invasive procedure for diagnosis during pregnamncy
Invasive & non invasive procedure for diagnosis during pregnamncyInvasive & non invasive procedure for diagnosis during pregnamncy
Invasive & non invasive procedure for diagnosis during pregnamncypreetishukla38
 
Amniocentesis ((Slide Show))
Amniocentesis ((Slide Show))Amniocentesis ((Slide Show))
Amniocentesis ((Slide Show))Caleb Smith
 
Assisted reproductive techniques
Assisted reproductive techniquesAssisted reproductive techniques
Assisted reproductive techniquesdrmcbansal
 
assisted reproductive technology
assisted reproductive technologyassisted reproductive technology
assisted reproductive technologyRudra madhab
 
In vitro fertilization
In vitro fertilizationIn vitro fertilization
In vitro fertilizationAnwar Siddiqui
 
Genetic counselling
Genetic counsellingGenetic counselling
Genetic counsellingsindhujojo
 
In-Vitro Fertilization
In-Vitro FertilizationIn-Vitro Fertilization
In-Vitro FertilizationSonia John
 
Prenatal Genetic Diagnosis
Prenatal Genetic DiagnosisPrenatal Genetic Diagnosis
Prenatal Genetic DiagnosisDr.Yogesh D
 
Amniocentesis ,CVS and karyotyping
Amniocentesis ,CVS and karyotypingAmniocentesis ,CVS and karyotyping
Amniocentesis ,CVS and karyotypingDrPoojaPandey4
 
Artificial Reproductive Technology
Artificial Reproductive TechnologyArtificial Reproductive Technology
Artificial Reproductive Technologyhealth sector
 
in vitro fertilization
in vitro fertilizationin vitro fertilization
in vitro fertilizationdamarisb
 
Chorionic villus sampling
Chorionic villus    samplingChorionic villus    sampling
Chorionic villus samplingHafiz M Waseem
 

What's hot (20)

amniocentesis.pptx
amniocentesis.pptxamniocentesis.pptx
amniocentesis.pptx
 
Genetic counselling & Prenatal Diagnosis
Genetic counselling & Prenatal Diagnosis Genetic counselling & Prenatal Diagnosis
Genetic counselling & Prenatal Diagnosis
 
Amniocentesis
AmniocentesisAmniocentesis
Amniocentesis
 
Prenatal diagnosis
Prenatal diagnosisPrenatal diagnosis
Prenatal diagnosis
 
Amniocentesis
AmniocentesisAmniocentesis
Amniocentesis
 
Invasive & non invasive procedure for diagnosis during pregnamncy
Invasive & non invasive procedure for diagnosis during pregnamncyInvasive & non invasive procedure for diagnosis during pregnamncy
Invasive & non invasive procedure for diagnosis during pregnamncy
 
Amniocentesis ((Slide Show))
Amniocentesis ((Slide Show))Amniocentesis ((Slide Show))
Amniocentesis ((Slide Show))
 
Assisted reproductive techniques
Assisted reproductive techniquesAssisted reproductive techniques
Assisted reproductive techniques
 
assisted reproductive technology
assisted reproductive technologyassisted reproductive technology
assisted reproductive technology
 
In vitro fertilization
In vitro fertilizationIn vitro fertilization
In vitro fertilization
 
Genetic counselling
Genetic counsellingGenetic counselling
Genetic counselling
 
Fetal therapy
Fetal therapyFetal therapy
Fetal therapy
 
In-Vitro Fertilization
In-Vitro FertilizationIn-Vitro Fertilization
In-Vitro Fertilization
 
Prenatal Genetic Diagnosis
Prenatal Genetic DiagnosisPrenatal Genetic Diagnosis
Prenatal Genetic Diagnosis
 
IUGR
IUGRIUGR
IUGR
 
Amniocentesis ,CVS and karyotyping
Amniocentesis ,CVS and karyotypingAmniocentesis ,CVS and karyotyping
Amniocentesis ,CVS and karyotyping
 
Artificial Reproductive Technology
Artificial Reproductive TechnologyArtificial Reproductive Technology
Artificial Reproductive Technology
 
in vitro fertilization
in vitro fertilizationin vitro fertilization
in vitro fertilization
 
Amniocentesis
AmniocentesisAmniocentesis
Amniocentesis
 
Chorionic villus sampling
Chorionic villus    samplingChorionic villus    sampling
Chorionic villus sampling
 

Viewers also liked

Viewers also liked (6)

Prenatal diagnosis
Prenatal diagnosis Prenatal diagnosis
Prenatal diagnosis
 
Sridhar prenatal diagnosis
Sridhar prenatal diagnosisSridhar prenatal diagnosis
Sridhar prenatal diagnosis
 
Amniotic fluid
Amniotic fluidAmniotic fluid
Amniotic fluid
 
amniotic fluid analysis
amniotic fluid analysisamniotic fluid analysis
amniotic fluid analysis
 
Prenatal diagnosis
Prenatal diagnosisPrenatal diagnosis
Prenatal diagnosis
 
prenatal diagnosis
prenatal diagnosis prenatal diagnosis
prenatal diagnosis
 

Similar to Cordocentesis, Fetoscopy, Triple Test, PGD Diagnostic Tests

acn-prenataldiagnosis-101013214352-phpapp02.pdf
acn-prenataldiagnosis-101013214352-phpapp02.pdfacn-prenataldiagnosis-101013214352-phpapp02.pdf
acn-prenataldiagnosis-101013214352-phpapp02.pdfAbisha62
 
Interdprtmntal seminar
Interdprtmntal seminarInterdprtmntal seminar
Interdprtmntal seminardrmcbansal
 
Pg dreview
Pg dreviewPg dreview
Pg dreviewt7260678
 
1 s2.0-s0015028214020809-main
1 s2.0-s0015028214020809-main1 s2.0-s0015028214020809-main
1 s2.0-s0015028214020809-main鋒博 蔡
 
Pre implantation genetic diagnosis (pgd)
Pre implantation genetic diagnosis (pgd)Pre implantation genetic diagnosis (pgd)
Pre implantation genetic diagnosis (pgd)BALASUBRAMANIAM IYER
 
FISH IN DIAGNOSTICS
FISH IN DIAGNOSTICSFISH IN DIAGNOSTICS
FISH IN DIAGNOSTICSKumar Lav
 
Genetic screening..dr.padmesh
Genetic screening..dr.padmeshGenetic screening..dr.padmesh
Genetic screening..dr.padmeshv_padmesh
 
Mjd presentation1
Mjd presentation1Mjd presentation1
Mjd presentation1鋒博 蔡
 
Mjd presentation1
Mjd presentation1Mjd presentation1
Mjd presentation1鋒博 蔡
 
Mjd presentation1 (4)
Mjd presentation1 (4)Mjd presentation1 (4)
Mjd presentation1 (4)t7260678
 
Mjd presentation1 (1)
Mjd presentation1 (1)Mjd presentation1 (1)
Mjd presentation1 (1)t7260678
 
Mjd presentation1 (3)
Mjd presentation1 (3)Mjd presentation1 (3)
Mjd presentation1 (3)t7260678
 
Mjd presentation1 (5)
Mjd presentation1 (5)Mjd presentation1 (5)
Mjd presentation1 (5)t7260678
 
Mjd presentation1 (2)
Mjd presentation1 (2)Mjd presentation1 (2)
Mjd presentation1 (2)t7260678
 
Mjd presentation1
Mjd presentation1Mjd presentation1
Mjd presentation1鋒博 蔡
 
Genetictesting 140305094745-phpapp01
Genetictesting 140305094745-phpapp01Genetictesting 140305094745-phpapp01
Genetictesting 140305094745-phpapp01t7260678
 
pregnancy &prenatal diagnosisi
pregnancy &prenatal diagnosisipregnancy &prenatal diagnosisi
pregnancy &prenatal diagnosisiPALANIANANTH.S
 

Similar to Cordocentesis, Fetoscopy, Triple Test, PGD Diagnostic Tests (20)

acn-prenataldiagnosis-101013214352-phpapp02.pdf
acn-prenataldiagnosis-101013214352-phpapp02.pdfacn-prenataldiagnosis-101013214352-phpapp02.pdf
acn-prenataldiagnosis-101013214352-phpapp02.pdf
 
Interdprtmntal seminar
Interdprtmntal seminarInterdprtmntal seminar
Interdprtmntal seminar
 
Pg dreview
Pg dreviewPg dreview
Pg dreview
 
Pg dreview
Pg dreviewPg dreview
Pg dreview
 
Pg dreview
Pg dreviewPg dreview
Pg dreview
 
1 s2.0-s0015028214020809-main
1 s2.0-s0015028214020809-main1 s2.0-s0015028214020809-main
1 s2.0-s0015028214020809-main
 
Pre implantation genetic diagnosis (pgd)
Pre implantation genetic diagnosis (pgd)Pre implantation genetic diagnosis (pgd)
Pre implantation genetic diagnosis (pgd)
 
Uu
UuUu
Uu
 
FISH IN DIAGNOSTICS
FISH IN DIAGNOSTICSFISH IN DIAGNOSTICS
FISH IN DIAGNOSTICS
 
Genetic screening..dr.padmesh
Genetic screening..dr.padmeshGenetic screening..dr.padmesh
Genetic screening..dr.padmesh
 
Mjd presentation1
Mjd presentation1Mjd presentation1
Mjd presentation1
 
Mjd presentation1
Mjd presentation1Mjd presentation1
Mjd presentation1
 
Mjd presentation1 (4)
Mjd presentation1 (4)Mjd presentation1 (4)
Mjd presentation1 (4)
 
Mjd presentation1 (1)
Mjd presentation1 (1)Mjd presentation1 (1)
Mjd presentation1 (1)
 
Mjd presentation1 (3)
Mjd presentation1 (3)Mjd presentation1 (3)
Mjd presentation1 (3)
 
Mjd presentation1 (5)
Mjd presentation1 (5)Mjd presentation1 (5)
Mjd presentation1 (5)
 
Mjd presentation1 (2)
Mjd presentation1 (2)Mjd presentation1 (2)
Mjd presentation1 (2)
 
Mjd presentation1
Mjd presentation1Mjd presentation1
Mjd presentation1
 
Genetictesting 140305094745-phpapp01
Genetictesting 140305094745-phpapp01Genetictesting 140305094745-phpapp01
Genetictesting 140305094745-phpapp01
 
pregnancy &prenatal diagnosisi
pregnancy &prenatal diagnosisipregnancy &prenatal diagnosisi
pregnancy &prenatal diagnosisi
 

More from Sanil Varghese (20)

Traction
TractionTraction
Traction
 
Splints
SplintsSplints
Splints
 
Prosthetics
ProstheticsProsthetics
Prosthetics
 
Plaster casts
Plaster castsPlaster casts
Plaster casts
 
Osteoporosis
OsteoporosisOsteoporosis
Osteoporosis
 
Orthopedics radiography sanil
Orthopedics radiography sanilOrthopedics radiography sanil
Orthopedics radiography sanil
 
Orthopedic implants
Orthopedic implantsOrthopedic implants
Orthopedic implants
 
Orthopedic beds
Orthopedic bedsOrthopedic beds
Orthopedic beds
 
Myopathies
MyopathiesMyopathies
Myopathies
 
Musculoskeletal
MusculoskeletalMusculoskeletal
Musculoskeletal
 
Musculo skeletal disorders
Musculo skeletal disordersMusculo skeletal disorders
Musculo skeletal disorders
 
Gout
GoutGout
Gout
 
Fractures
FracturesFractures
Fractures
 
Braces
BracesBraces
Braces
 
Bones
BonesBones
Bones
 
Bone tumors
Bone tumorsBone tumors
Bone tumors
 
Peripheral nerve disrders
Peripheral nerve disrdersPeripheral nerve disrders
Peripheral nerve disrders
 
Peripheral nerve disorders
Peripheral nerve disordersPeripheral nerve disorders
Peripheral nerve disorders
 
Myasthenia gravis new
Myasthenia gravis newMyasthenia gravis new
Myasthenia gravis new
 
Meningitis
MeningitisMeningitis
Meningitis
 

Cordocentesis, Fetoscopy, Triple Test, PGD Diagnostic Tests

  • 2. CORDOCENTESIS FETOSCOPY TRIPLE TEST PRE-IMPLANTATION GENETIC DIAGNOSIS POLAR BODY BIOPSY BLASTOMERE BIOPSY KARYOTYPING GENE MAPPING
  • 3. Cordocentesis, also sometimes called Percutaneous Umbilical Cord Blood Sampling (PUBS), is a diagnostic test that examines blood from the fetus to detect fetal abnormalities. Cordocentesis is performed after 17 weeks of pregnancy.
  • 4. An advanced imaging ultrasound determines the location where the umbilical cord inserts into the placenta. The ultrasound guides a thin needle through the abdomen and uterine walls to the umbilical cord. The needle is inserted into the umbilical cord to retrieve a small sample of fetal blood.
  • 6. PURPOSE To Help In Diagnosis Of: Malformations of the fetus. Fetal infection (i.e. toxoplasmosis or rubella) Fetal platelet count in the maternal circulation. Fetal anemia. Isoimmunisation.
  • 7. COMPLICATION Blood loss from the puncture site Infection Drop in fetal heart rate Premature rupture of membranes Fever Chills Leaking of amniotic fluid
  • 8. Fetoscopy is an endoscopic procedure during pregnancy to allow access to the fetus, the amniotic cavity, the umbilical cord, and the fetal side of the placenta. It is done during & after 18 weeks of pregnancy
  • 9. PROCEDURE A small (3–4 mm) incision is made in the abdomen, and an fetoscope is inserted through the abdominal wall and uterus into the amniotic cavity. Fetoscopy allows medical interventions such as a biopsy or a laser occlusion of abnormal blood vessels.
  • 11. PURPOSE Evaluate the fetus for birth defects, such as spina bifida as well as other defects which can only be confirmed by a Fetoscopy. To collect samples of blood from the umbilical cord, e.g. hemophilia or sickle cell anemia. Collect samples of skin tissue from the fetus. The tissue can be tested for some
  • 12. COMPLICATIONS Miscarriage, as high as 12%. Excessive bleeding, infection, or excessive leakage of the amniotic fluid. Preterm rupture of the membranes. Mixing mother’s blood with baby’s blood.
  • 13. Also called as “Triple screen“, the “Kettering test”, the “Bart's test” or "Multiples of the Median (MoM)“. 3 tests: • Maternal Serum Alpha-fetoprotein (MSAFP) • Unconjugated estriol • Human chorionic gonadotropin (hCG)
  • 14. The triple test is an investigation performed during pregnancy in the second trimester (15-18 weeks) to classify a patient as either high-risk or low-risk for chromosomal abnormalities (and neural tube defects). The triple screen test involves drawing blood from the mother. The blood sample is then sent to the laboratory for testing. AFP is is produced in the yolk sac and fetal liver.
  • 15. INCREASED MSAFP UE3 hCG RISK OF DOWN’S ↓ ↓ ↑ SYNDROME TRISOMY 18 ↓ ↓ ↓ NTD’s ↑ NORMAL NORMAL MOLAR ↓ ↓ ++↑ PREGNANCY MULTIPLE ↑ NORMAL ↑ GESTATION
  • 16. PRE-IMPLANTATION GENETIC DIAGNOSIS / EMBRYO SCREENING As PGD can be performed on cells from different developmental stages, the biopsy procedures vary accordingly. Theoretically, the biopsy can be performed at all preimplantation stages, but only three have been suggested: on unfertilised and fertilised oocytes (for polar bodies, PBs), on day three cleavage-stage embryos (for blastomeres) and on blastocysts (for trophectoderm cells).
  • 17. ADVANTAGES Helps prevents birth of children with chromosomal anomalies and single gene disorders. Eugenics.
  • 18. POLAR BODY BIOPSY The first and second polar body of the oocyte are extruded at the time of the conclusion of the meiotic division, normally the first polar body is noted after ovulation, and the second polar body after fertilization.
  • 19. By analyzing polar bodies it is possible to study maternal genetic makeup. The disadvantage of polar body biopsy is that, it detect paternally derived chromosomal disorders & single gene disorders (autosomal dominant disorders, autosomal recessive disorders and sex-linked disorders).
  • 20. BLASTOMERE BIOPSY It is also called Embryo biopsy, Cleavage- stage biopsy. Cleavage-stage biopsy is generally performed the morning of day three post- fertilization, when normally developing embryos reach the eight-cell stage. A hole is made in the zona pellucida and one or two blastomeres containing a nucleus are gently aspirated or extruded through the opening.
  • 21. ADVANTAGE The genetic input of both parents can be studied.
  • 22. Karyotyping It is the procedure by which the chromosomes are arranged based on the sizes, position of the centromere & pattern of the chromosome binding
  • 23. • The test can be performed on a sample of blood, bone marrow, amniotic fluid, or tissue from the placenta.The sample is placed into a special dish and allowed to grow in the laboratory. Cells are later taken from the growing sample and stained. The laboratory specialist uses a microscope to examine the size, shape, and number of chromosomes in the cell sample.
  • 24. The stained sample is photographed to provide a karyotype, which shows the arrangement of the chromosomes. Certain abnormalities can be identified through the number or arrangement of the chromosomes. Chromosomes contain thousands of genes that are stored in DNA, the basic genetic material.
  • 25. GENE MAPPING Gene mapping, also called genome mapping, is the creation of a genetic map assigning DNA fragments to chromosomes.
  • 26. TYPES 1. Genetic mapping:- The relative position between 2 genes of a chromosome are determined using linkage analysis. 2. Physical mapping:- Using techniques like FISH technique, it is possible to determine the absolute position of a gene on a chromosome.
  • 27. Fluorescent In Situ Hybridization (FISH) FISH is the most commonly applied method to determine the chromosomal constitution of an embryo. In contrast to karyotyping, it can be used on interphase chromosomes, so that it can be used on PBs & blastomeres. The cells are fixated on glass microscope slides and hybridized with DNA probes. Each of these probes are specific for part of a chromosome, and are labelled with a fluorochrome.
  • 28. The use of probes for chromosomes X, Y, 13, 14, 15, 16, 18, 21 and 22 has the potential of detecting 70% of the aneuploidies found in spontaneous abortions. In order to be able to analyse more chromosomes on the same sample, up to three consecutive rounds of FISH can be carried out.