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Saturday, August 7, 2010

Avoiding overlaps in chromosome image (karyotypes)

I have received a question about human cytogenetics (chromosome or karyotype analysis).

I am doing a project in detecting the numerical abnormalities in chromosomes. Is it possible to get the microscopic chromosome images without any overlaps? ... mail me your suggestions.
I'm mailing you a sample image. The chromosomes in this image are overlapped and have crossovers. Is it possible to have the microscopic image without this type of crossovers. When I try to count the number of chromosomes the chromosomes that have crossovers and overlaps are counted as one. And my research concept is not mainly on this overlaps. So I'm trying for images without overlaps and crossovers. My concept is based on classification of the chromosomes so I need good well spread image

I have no training in cytogenetics per se, so I invite replies from those with such training (either academic human cytogeneticists or clinical laboratory specialists in cytogenetics (CLSp(CG)). As usual, answers should be provided in the form of comments from identified people with relevant expertise.

It seems to me that there are two questions here. One concerns the technical issue of whether it is possible to routinely obtain spreads without overlapping chromosomes. The other is whether there are already standard methods for dealing with this problem in the image analysis.

3 comments:

  1. It is possible to take the overlaps off If two images can be obtained. One image is taken from one side and the other image is taken from the other side. Image processing method can isolate two chromosomes that are overlapped and have crossovers.

    ReplyDelete
  2. It is possible to take the overlaps off If two images can be obtained. One image is taken from one side and the other image is taken from the other side. Image processing method can isolate two chromosomes that are overlapped and have crossovers.

    ReplyDelete
  3. It is possible to obtain metaphase chromosome spreads that have no overlaps, but it is not the norm. More than 90% of the metaphase spreads I see daily have overlaps in them. The longer the chromosomes the more likely they are to have overlaps. The pictures you have may be manipulated so that chromosomes that are overlapped are "cut apart" using Photo Shop, Paint, Art Weaver etc. In a clinical setting, computer programs specifically designed to karyotype metaphase spreads are used to "cut apart" these overlaps.

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