Complete worms of diverse T. spiralis developmental stages (ML, 6h and 12h IIL, 3d and 6d AW, and NBL) were fixed with 4% formaldehyde for 30 min. The fixed worms were embedded in paraffin and cut into a 2-μm thick cross-section with a microtome. Expression and tissue location of native TsSP1.1 in diverse stage worms was observed using IIFA. Complete worms and their cross-sections were blocked with 5% normal goat serum for 2 h, and then incubated at 37 °C for 2 h with 1:10 diluted various sera. Following washes with PBS, the worms were stained by goat anti-mouse IgG-FITC conjugate (1:100; Santa Cruz, USA). After washes again, complete worms and cross-sections were observed under fluorescence microscopy (11 (link)).