The Human chromosome aberration is a huge field of investigation, what kind of aberration do you want to detect? What kind of tissue do you used to detect this aberrations?

luis

Hello sir,

i am working with pha induced whole blood cultre and harvested metaphases for  diagnosis of different genetic disorder.i'm interested in detection of  deletion and translocation which are seen in majority of suspected cases.specially In those cases where we found new or rare structural anomalies.

Somprakash D.

we do get various locus specific probes (xcying DNA probe kits) from meta systems (www.metasystems-asia.com). You can check for the probes of your interest. As u mentioned, if want to study unknown deletion and translocation events, u can do a regular karyotyping using chromosome paints too though it needs good imaging systems.

Hi Kalyani,

Thank you for the answering,Is there any limitation of whole chromosome paint method for the detection of novel translocation or deletion .Partial trisomy and partial monosomy can detecte by this method? I have few cases of partial trisomy and monosomy, for that I’m looking for confirmatory method.

Somprakash D.

Yes. Partial trisomy and monosomy can be very well be detected. (Though I haven't done this myself, it is possible to do it).  Translocations can be figured easily but not sure if fine deletion can be  detected.You can either go for couple of probes to study two chromosomes of interest or select a list of chromosomes. Check for imaging facilities available and affordability.

Hello, could you please explain in more details what your problems with FISH exactly are?

As, Kalyani already said you can use commercially available probes, metasystems ones are excellent, and you can use mFISH probes for translocations. However, the resolution is quite the same that karyotyping...so, you will only see quite "big" (Mb) intrachromosomal rearrangements. And if you want to see microdeletions you should use other techniques, and loci specific probes.

You should use an hybrite for denaturation-hybridation steps which gives better results than manual method. And for karyotyping you should use a motorized microscope, equipped of metaphases search software (Metasystems again for example).

Somprakash 

to detect microdeletions by FISH you need first a good clinical diagnosis, in order to suspect an specific sindrome and them you use locus specific probes (LSI probes) to corroborate or not your suspect. In Cuba during several years we use the FISH with out hybrider, really is very difficult but possible. I recomend the Vysis probe,are wonderful . Look for a catalogue of vysis,available in internet, and you will have a better idea about differents probes use for each diseases. M fish is not good to detect delection or inversions. what is your country?

luis

what protocol of FISH you are using now? M-Fish,LSI probe ?

Thank you Elodie.

With pleasure, but I'm sure we could be of better help if you tell us more about your FISH troubles. Are you working in a cytogenetic centre? Do you have access to hybridizers or motorized microscope?

Hi Luis and Elodie,

I  belong from india and working in a cytogenetics lab.Our institute is a diagnostic cum research centre.I'm doing fish using  manual method by separate denaturation of sample and probe (LSI,partial paint- vysis, whole chromosome paint- Createch ).We were getting satisfactory results by above said protocol but recently i'm not getting good results.Signals are not seen in the microscope or looking very faint in the camera pics.We are using ziess 90i fluroscent microscope facilitate with image capture system but not facilitate with metaphase search software.i'm trying to troubleshoot the problem but it not help me. I'm using the same reagent and equipment. UV Filter could be the reason??

Elodie we don't have hybridizer.We do manually  all the process.

Hi Somprakash

I send to you an imagen of a cube to do FISH. Is this kind of filter, are you using? this filter is very good really.