Isolation of DNA sequences.

The purpose of this study involves the separation of DNA fragments that can detect existing mutations of genes responsible for certain hereditary diseases.

Polymerase chain reaction (PCR).

This method allows to amplify specific DNA sequences of small samples, allowing them to do further analysis.

Fluorescence hybridization in situ (FISH)

This method provides specific labeling by fluorescence study of the chromosome. The result of this analysis allows us to identify the number of copies of certain chromosomes and possible structural damages.

All of these methods are used to meet the needs of the center in the field of genetics and molecular biology.

The procedures which take place in the department of molecular biology are as followed.

Prenatal diagnosis

Prenatal diagnosis can detect genetic and chromosomal abnormalities before birth. The research may be conducted by amniocentesis (removal of amniotic fluid) and biopsy hormonal villi. This diagnosis allows to define:

- The correct number of chromosomes by FISH.

- Changes in the structure of chromosomes.

- Genetic studies of hereditary diseases.

- Cytogenetic studies (chromosome analysis)

Classic cytogenetic studies, as well as by FISH, can detect in peripheral blood and tissue biopsies structural damage and micro deletions.

Genetic studies

Genetic studies include various genetic diseases and disorders like:

• Filtering mutation cystic fibrosis (33 mutations plus polymorphisms 5T/7T/9T).

• Investigation of the expansion, which is responsible for the syndrome, fragile X chromosome.

• Filtering ataxia.
Investigation of moronic dystrophy.
Study of markers of Duchene muscular dystrophy.

The study of Huntington's chorea.

• Investigation of methylation and parthenogenesis disomic Prodder-Willie-Engelmann.

• Molecular diagnosis of hemochromatosis.

The study of male factor

Currently, the parameters obtained by analyzing the sperm (semen), do not provide complete information about the fertilizing capacity of sperm, the ability to conceive a healthy embryo and normally developing pregnancy. A complete investigation of male factor and its role in fertility couples require a determination of some other parameters, including:

FISH in spermatozoa:

With the previously described method FISH determined changes in the number of chromosomes (aneuploidy) in spermatozoa. Increasing the number of sperm with disabilities may cause failure of implantation and miscarriage.

Filtering micro deletion of chromosome Y:

PCR method to detect the possible deletion of various specific regions of chromosome Y. Proved that the absence of these sites causes various disorders in gametogenesis.

Determination of the index of DNA fragmentation in sperm (TUNNEL):

It was shown that infertile men have a greater number of sperm with DNA breaks and that this may affect the outcome of assisted reproduction.

The method used to identify DNA fragmentation in sperm, called TUNNEL or Terminal DUTP Nick-End Labeling, it is to measure the existing gaps in the chain of DNA by introducing molecules with fluorescent labels.

Pre implantation genetic diagnosis

Pre implantation genetic diagnosis (PGD) is a diagnosis of chromosomal and genetic disorders of an embryo before its transfer of the mother.

PGD can identify embryos lacking the chromosomal and genetic mutations. Its purpose is to ensure a healthy sperms and preventing the transmission of certain diseases.

First of all, genetics and molecular biologists carefully evaluate each case. Then develop individual technique for diagnosing future embryos.

The couple must undergo In Vitro Fertilization (IVF). Usually, fertilization using sperm injection method. Scientists wait three days to receive this procedure embryos reached the stage of the division of six to eight cells. At this stage the embryonic biopsy, if the required stage of division was not met, to do a biopsy is not recommended, as it reduces the viability of the embryo.

Taken blastomeric undergo analysis in the laboratory of molecular biology, and the embryos from which they were removed, continue to grow until the genetic diagnosis. The aim is to transfer healthy in the process of embryo development, which will ensure the normal development of pregnancy.

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