Figure 4 .

Fluorescence in situ hybridisation to detect the Y chromosome-containing cells in the biopsy specimens of the labial salivary glands. The Y chromosome probe was labelled with fluorescein (green signal), and the X chromosome probe was labelled with rhodamine red (red signal). (A) A female patient without SS (a negative control). Nucleus containing two X chromosomes (red signals). (B) A male patient with SS (a positive control). Nucleus containing one X chromosome (red signal) and one Y chromosome (green signal). (C, D, E) Female patients with SS who tested positive for the Y chromosome-specific sequence by PCR (Nos 40, 41, and 49, respectively) (study subjects). White arrow, nucleus containing one Y chromosome (green signal); red arrow, nucleus containing two X chromosomes (red signals).