Sentence:  Membranes were blocked at RT for 2 h with <WSD>blotto</WSD> [50 mM Tris pH 7.5, 0.185 mM NaCl, 0.05% Tween-20, 3% nonfat dry milk]. Ape1 monoclonal antibody developed in our laboratory (Novus Biologicals, Littleton, CO, USA) was diluted in <WSD>blotto</WSD> and incubated with the membrane overnight at 4°C (1:1000). 
Meaning of the word marked with <WSD> tags:  A reagent made from non-fat dry milk, phosphate buffered saline, and sodium azide, which is used to block protein binding sites for laboratory techniques such as blots and the enzyme-linked immunosorbent assay (ELISA).