Methodology
Immunohistochemistry (IHC)
Test Description
Paired Box 5 (PAX5) is a B-cell specific activator protein (BSAP). In early stages of B-cell development, PAX5 influences the expression of several B-cell specific genes, such as CD19 and CD20. PAX5 is expressed primarily in pro-, pre-, and mature B-cells, but not in plasma cells. There is an excellent correlation between CD20 and PAX5 expression; however, anti-PAX5 exceeds the specificity and sensitivity of L26 (CD20) because of its earlier expression in B-cell differentiation and its ability to detect all committed B-cells, including classic Hodgkin lymphoma. It is very specific to B-cell lineage and does not stain T-cells.
Specimen Requirements
- A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type
or - One (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4-5 microns) for each test/antibody ordered
- Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Storage & Transportation
Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.
CPT Code(s)*
88342 x 1 or 88341 x 1
Turnaround Time
24 hours
Level of Service
Stain Only
New York Approved
Yes