A method of sticking each of identification information labels (50) indicating donor-identification information (BC) that is to be assigned to each donor on corresponding one of a plurality of blood collection tubes (30) for containing a medical fluid of the each donor, the method includes: arranging the plurality of blood collection tubes (30) side by side; and sticking the separably united identification information labels (50) as many as the blood collection tubes (30) on the plurality of blood collection tubes (30) arranged side by side.