PTP1 reactivity with ConA is seen in multiple microsporidia. Solubilized (2% DTT) polar tube preparations of five microsporidia species, G. americanus (Ga), E. hellem (Eh), E. cuniculi (Ec), E. intestinalis (Ei), and B. algerae (Ba), were used for a lectin overlay with labeled ConA. ConA reacted with a band in each polar tube preparation that had a size consistent with that seen on SDS-PAGE and immunoblot analysis with antibody to PTP1 (12-15).