Test ID: TLBLF    
T-Lymphoblastic Leukemia/Lymphoma, FISH, Tissue

This test uses FISH enumeration strategy probes to detect deletions of CDKN2A(p16) on chromosome 9p and TP53 on chromosome 17p. Dual-color, break-apart (BAP) probes are used to detect rearrangements of the TAL1/STIL(SIL), TRB(TCR beta), MLL, and TRAD(TCR alpha delta) locus on 1p33, 7q34, 11q23, and 14q11.2, respectively. Dual-color, dual-fusion strategy (D-FISH) probe sets are used to detect fusions of the TLX3(HOX11L2)/BCL11B, ABL1(ABL)/BCR, and MLLT10(AF10)/PICALM  locus on (5;14)(q35;q32), (9;22)(q34;q11.2), and (10;11)(p12;q14) respectively. D-FISH probe sets are also used in reflext testing when rearrangements of MLL, TRAD(TCR alpha delta) and TRB(TCR beta) gene loci are detected. Amplification of the ABL1 gene is detected using a D-FISH probe strategy. Paraffin-embedded tissues are cut at 5 microns and mounted on positively charged glass slides. The selection of tissue and the identification of target areas on the hematoxylin and eosin- (H and E) stained slide are performed by a pathologist. Using the H and E-stained slide as a reference, target areas are etched with a diamond-tipped etcher on the back of the unstained slide to be assayed. For each probe set, the probes are hybridized to the appropriate target areas and 2 technologists each analyze 50 interphase nuclei (100 total) per probe set with the results expressed as the percent abnormal nuclei.(Unpublished Mayo method)

Specimens are processed Monday through Sunday.

Results reported Monday through Friday, 8 a.m.-5 p.m.