Skip to Content

Are you based in North America? If yes, switch to our North American website →

MLL/AFF1 Translocation, Dual Fusion

Catalogue Numbers
LPH 081-S (5 tests)
LPH 081 (10 tests)

Probe Specification

  • MLL, 11q23.3, Green
  • AFF1, 4q21.3-q22.1, Red

The MLL probe, labelled in green, covers a 200kb region including the MLL (KMT2A) gene. The AFF1 probe, labelled in red, consists of four clones (220kb, 61kb, 110kb and 211kb) covering the AFF1 gene and surrounding regions.

Probe Information

The t(4;11)(q21;q23) translocation that involves the MLL (KMT2A) gene, on chromosome 11q23.3, and the AFF1 gene, on chromosome 4q21.3-q22.1, is the most frequently observed translocation involving the MLL gene in Acute Lymphoblastic Leukaemia (ALL)1.

The t(4:11) translocation results in the generation of two reciprocal fusion genes: MLL/AFF1 and AFF1/MLL – the leukaemic properties of the first have been documented but the role of the AFF1/MLL fusion protein is still under debate2,3,4.

The 2011 Acute Lymphoblastic Leukaemia Best Practice Guidelines5 state that: “The t(4;11)(q21;q23) is associated with a poor prognosis, and patients with this translocation may be treated on the high risk arm of MRC protocols”…“If chromosome analysis is unsuccessful but FISH indicates a rearrangement of MLL, then further attempts to identify the t(4;11) must be made.”

The MLL/AFF1 Translocation, Dual Fusion probe allows both fusion genes, generated by the t(4;11)(q21;q23) translocation, to be detected.

The quality of the products we have received from Cytocell have been excellent. The FISH probes they provide to us give intense, strong signals and are a pleasure to count. What has really stood out however has been the level of support and assistance provided by Cytocell’s application specialists. The team worked very closely alongside our own during the adoption of this product and spent many hours with us perfecting the technique, going above and beyond what I would expect during the transition period. Source BioScience absolutely demand high quality products and service to be able to deliver our results with confidence, and that is what we have received from Cytocell. Neil Ryan, Laboratory Operations Manager at Source BioScience 


1. Meyer et al., Leukemia 2009;23(8):1490-9

2. Smith et al., Genes Dev. 2011;25(7): 661–72

3. Kumar et al., Leuk Res. 2011;35(3):305-9

4. Bursen et al., Blood. 2010; 29;115(17):3570-9

5. Professional Guidelines for Clinical Cytogenetics: ACUTE LYMPHOBLASTIC LEUKAEMIA BEST PRACTICEGUIDELINES (2011) V1.00.

Microscope Images

MLL AFF1 Translocation Dual Fusion magnified
Area of Interest*


This product is intended to be used on Carnoy’s solution (3:1 methanol/acetic acid) fixed haematological samples.

*Disease information supported by the literature and is not a reflection of the intended purpose of this product.