rosette test

ro·sette test

a test for rosette-forming cells (T lymphocytes) in which these cells and sheep erythrocytes are incubated and centrifuged lightly, then examined under a microscope for rosette formation or adherence of erythrocytes to T lymphocytes.

A qualitative screening test for detecting significant—10 ml—foetomaternal haemorrhage, where indicator cells form easily identified rosettes around individual Rh-D foetal cells that may be present in the Rh-negative mother; a positive RT should be followed by a quantitative test—e.g., the Kleihauer-Betke test