Subtelomere FISH analysis is a commonly used as an adjunct to routine cytogenetic testing in order to detect small rearrangements involving the telomeric regions of chromosomes. Patients can be referred for telomere analyses for a number of different reasons, including genetic disease, autistic disorders, unexplained mental retardation/developmental delay, recurrent miscarriages and haematological malignancies1-4.
CytoCell's® TeloMark kit consists of 41 subtelomere specific probes, three centromere and six locus specific probes (50 different probes in total). The subtelomere probes represent all chromosome ends apart from the p-arms of the five acrocentric chromosomes and with no distinction between the X and Y due to clones being located in the pseudoautosomal regions. All of these probes map to unique regions of the chromosomes, within 850kb of the true telomere.
The probes in TeloMark are provided as 15 separate mixes, either provided individually or as a kit containing all 15. All probes are directly labelled in orange, green, yellow (orange and green combined) or blue.
Running our PETS protocol was taking upwards of 5 hours to complete based on the previous SOP. After the technical training visit from CytoCell, we were able to make some tweaks to reduce the protocol time down to just 1 hour and 15 minutes, with the same or better results.
Assistant Genetic Technologist, Leicestershire Genetics Centre, UK