Figure 1: Subcellular localization of AMPK protein in human spermatozoa. AMPK was detected in human sperm using epifluorescence (a-c) or confocal (d-i) microscopy. Two different antibodies were used: from (a-f) anti-AMPK antibody against amino acids 181-185 and 170-174 of AMPKα subunit (Abcam) where (a) and (d) are bright field images, (b) and (e) are IgG-Alexa 488 images, and (c) and (f) are DAPI stained images; from (g-i) anti-AMPK antibody against amino acids 251-550 at the C-terminus of AMPKα subunit (Santa Cruz Technology) where (g) is bright field image, (h) is IgG-Alexa 488 image and (i) is DAPI stained image. Serial of confocal microscopy images (j-o) obtained from a unique spermatozoon using different focus depth (5 μm thickness) are shown by overlapping IgG-Alexa 488 (green) and DAPI (blue) staining after incubation with anti-AMPK antibody (Santa Cruz Technology). Images are representative of n = 6 experiments. Scale bars (5-10 μm) are indicated.