Detection of galectin-1 by confocal microscopy. (A) Freshly isolated and anti-CD3/anti-CD28–activated CD4⁺CD25⁻ and CD4⁺CD25⁺ T cells were fixed with 4% PFA and permeablized by 0.2% Triton X-100. Samples were stained with mouse anti–human galectin-1 mAb followed by FITC conjugated goat antimouse antibody (green). Cytoskeleton was stained by phalloidin-TRITC (red). (B) Images of fresh and activated human CD4⁺CD25⁺ T cells at high magnification showing the localization of galectin-1 inside the cells.