Immunolocalization of serine, threonine and tyrosine phosphorylated proteins in Giardia trophozoites. Interphase trophozoites were labeled with antibodies against phosphoserine (pSer), phosphothreonine (pThr), or phosphotyrosine (pTyr). Phospholabeling is shown in green, nuclei are labeled with DAPI and a merge image shows overlay between the two stains. Morphology is shown in a differential interference contrast (DIC) image of each trophozoite. Scale bar = 10 μm.