The histochemical localization of thymosin b4 was investigated for the first time in several bovine tissues, using the indirect immunofluorescent technique and the newly applied alkaline phosphatase anti-alkaline phosphatase (APAAP) antibody method. A polyclonal antiserum raised against the N-terminal fragment (1-14) of thymosin b4, showing less than 0.1% crossreactivity with the second b-thymosin in calf tissues, thymosin b9, was used. Positive reaction for thymosin b4 was observed in the cytoplasm of all tissues studied, i.e., bovine spleen, thymus, lung, liver, kidney, lymph nodes and cardiac muscle. The highest staining intensity was found in the cytoplasmic area of spleen and thymus, whereas in sections of muscle the reaction was very weak. In the latter case a relatively strong reaction was strictly located in the sarcolemn region of the myofibrils.

The histochemical localization of thymosin b4 was investigated for the first time in several bovine tissues, using the indirect immunofluorescent technique and the newly applied alkaline phosphatase anti-alkaline phosphatase (APAAP) antibody method. A polyclonal antiserum raised against the N-terminal fragment (1-14) of thymosin b4, showing less than 0.1% crossreactivity with the second b-thymosin in calf tissues, thymosin b9, was used. Positive reaction for thymosin b4 was observed in the cytoplasm of all tissues studied, i.e., bovine spleen, thymus, lung, liver, kidney, lymph nodes and cardiac muscle. The highest staining intensity was found in the cytoplasmic area of spleen and thymus, whereas in sections of muscle the reaction was very weak. In the latter case a relatively strong reaction was strictly located in the sarcolemn region of the myofibrils.