المحاضرة 3- وراثة عملي

Cytogenetic 

 

Cytogenetic 

 Cytogenetic:- is a branch of genetics that is

concerned with the study of the structure and function of the cell, especially the chromosomes. In the routine laboratory environment human cytogenetic is always concerned with light microscope studies of chromosomes.

علم الوراثة الخلوي : هو فرع من فروع علم الوراثة يهتم بدراسة الظواهر الوراثية وكيفية ارتباط الصِبغيات بسلوك الخلية، لا سيما سلوكها أثناء الانقسام المتساو والانقسام الاختزالي دون الحاجة إلى استخراج الحمض النووي وذلك عن طَريق استخدام المَجهر الضوئي.

Almost all human cytogenetic studies involve the examination of dividing cell population by blocking cell division at metaphase with an inhibitor of spindle formation. The nuclear membrane breaks down and chromosome condensation takes place as usual, but the chromosomes fail to organize themselves into a metaphase plate.

Cytogenetic Sample Collection:

1. Peripheral Blood:

Collect 10ml for adults and 1-3ml for infants of whole blood in preservative-free sodium heparin (green top vacutainer) OR in a sterile heparinized syringe. **Keep blood samples at room temperature.

Figure(1). Green top vacutainer contain Lithium Heparin

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• 2. Bone marrow Aspirate: collect up to 5ml in preservative-free sodium heparin (green top vacutainer) OR in a sterile heparinized syringe. 

• 3. Tissue Samples (Skin Biopsy, Solid Tumors, Lymph Nodes): Collect a 2mm punch or about 2-4mm' tissue section and immediately place in a sterile vial with 3-5ml cytogenetie tissue transport media (or sterile saline if media is not available).

طريقة اخذ العينة من العقد اللمفاوية lymoh nods

•  4, Amniotic Fluid: Collect 15-30ml of fluid obtained under sterile condițions into tissue culture tubes or sterile syringes.

•  5. Chorionic Villi, placental tissue, umbilical tissue, or fetal organ tissue: Collect about 2-4mm2 of villi, placental tissue, umbilical tissue, or fetal organ tissue and place in a sterile vial with 3-5ml cytogenetie tissuc transport media (or sterile saline if media is not available).