The cytogenetics symposia 2nd edition

Instrumentation in the Cytogenetics Laboratory. Autosomal Aneuploidy. Structural Chromosome Rearrangements. Sex Chromosomes and Sex Chromosome Abnormalities. Cytogenetics of Infertility. Prenatal Cytogenetics. Cytogenetics of Spontaneous Abortion. Chromosome Instability. Cytogenetics of Hematologic Neoplasms. Bickmore, W. Borgaonkar, D. Bullerdiek, J. Campbell , L. Cancer Cytogenetics. Methods and Protocols. Chen , H. Atlas of Genetic Diagnosis and Counseling. Clark M. Chromosomes - The complex code.

Clynes, M. Animal Cell Culture Techniques. Davis J. IRL Press, Oxford, De Vienne, D. Flandrin, G. Gorczyca, W. Gosden, J. Chromosome Analysis Protocols. Heim, S.

Eds Cancer Cytogenetics. Elgin, Sarah C. Note: This item in a secured electronic format pdf provided as a downloadable link.

The succeeding chapters, written by cytogenetic technologists, PhDs, and medical doctors from the United States and Canada, provide up-to-date information on a broad range of topics in both cytogenetics and molecular cytogenetics. Many chapters now include molecular information reflecting the increased recognition of diagnostic complementation of these arenas.

Several specific steps are crucial in both the chromosomal preparation and G-banding to ensure the best possible quality of the results. One of the variables which can affect the assay is the Colcemid incubation time. Insufficient time in Colcemid yields fewer metaphase spreads and longer, overlapped chromosomes. Longer incubation times in Colcemid will result in shorter and thicker chromosomes which are difficult to analyze.

Another important variable is the molarity of the hypotonic solution. While adding the Carnoy's Fixative solution, the first 5 ml must be added to the pellet while mixing. This ensures that all of the extra proteins are removed before storing the samples or preparing slides.

If in the case that the cells are not mixed well enough, a yellow protein cap will form on top of the pellet, which can cause complications during subsequent procedures. Proper slide preparation is essential. Flooding the slide with fixative immediately following dropping the cells on to the slide will also help chromosomes to spread.

Temperature and humidity, which affect how fast the cell suspension dries on to the slide, are other factors which affect chromosome spreading.

For G-Banding, the main factor that affects the quality of the chromosomes is the trypsin exposure times. With a longer trypsin exposure, chromosomes may appear diffused and swollen. Conversely, an inadequately short trypsin incubation will yield chromosomes with indistinguishable bands and little contrast. The trypsin incubation timing is subject to change depending on each specific cell line and harvesting conditions.

Therefore, a representative G-banded slide should be first prepared to evaluate the trypsin conditions before staining the rest of the slides. Fetal bovine serum is used to inactivate the trypsin activity prior to staining. This procedure is relatively inexpensive and effective to perform. G-banding can be used to diagnose chromosome abnormalities such as translocations, deletions, and aneuploidy which are commonly seen in malignancies, genetic disorders, and stem cells cultured in vitro 10,11, This provides the indispensable visualization of the chromosome constitution and the global evaluation of the entire genome in multiple cells.

It is commonly used in clinical and research laboratories worldwide for the diagnosis, prognosis, and therapeutic evaluation of cancer cells Prenatal and postnatal tissue samples are routinely evaluated for the identification of numerical and structural abnormalities which cause genetic disorders such as Down syndrome. Stem cells can be rapidly evaluated for the presence of chromosome instability. However, the resolution of G-banding is limited for the identification of microdeletions or complex chromosome abnormalities as seen in metastatic malignancies.

Therefore, when routine chromosome G-banding is supplemented with procedures such as fluorescence in situ hybridization FISH , comparative genomic hybridization CGH , and spectral karyotyping SKY , detection rates of chromosomal abnormalities are increased dramatically For this reason, the utilization of the present protocol in combination with these other molecular cytogenetic procedures is increasingly being used by different laboratories for the evaluation of chromosome instability in both the clinical and research setting Work described in this manuscript was made possible by funding from the Patrick F.

Taylor Foundation. National Center for Biotechnology Information , U. J Vis Exp. Published online Jan Author information Copyright and License information Disclaimer.

Correspondence to: Fern Tsien at ude. This article has been cited by other articles in PMC. Abstract Chromosome cytogenetic analysis is widely used for the detection of chromosome instability. Download video file. Introduction Chromosome analysis is a conventional technique utilized worldwide to diagnose chromosome instability and rearrangements leading to genetic disorders and malignancy 1,2,8,9.

Protocol 1. Modification to Protocol: Chromosome harvesting of lymphoblastoid cell lines Grow cells according to specific cell culturing conditions. Representative Results High quality metaphase spreads are essential for chromosome analysis.