Patient slides are enumerated following assessment and enumeration of the quality control (QC) slide. The patient slides should be assessed for the same parameters as the QC slide before enumeration is performed. Enumeration entails documenting the number of signals for each probe on an excel spreadsheet and then calculating the average of each probe. Normally, 60 TUMOR cells are counted. For some probes, as few as 20 cells are counted while for other probes as many as 200 cells are counted.
In the image, there are 3 green centromere signals, indicating aneuploidy of chromosome 10. There is 1 orange PTEN signal, which indicates a relative loss of PTEN. This means that the PTEN gene was lost on 2 of the chromosomes.
