[en] The researches ^99mTc recovery process at presence of divalent Sn(II) were made to determine necessary and sufficient amount of Sn(II), which would provide its full reducibleness in the reaction mixture. That the solution of ^99mTc eluate reacts directly with the solution of modified DTPA and SnCl₂ the content of radiochemical impurity (RCI) of the unreduced ^99mTc(VII) in the labeled nanocolloid is 2.7 %, while the yield of the nanocolloid with the size of 100 nm is approximately 80 %. The results of researches prove the nanocolloid actively gets into the lymphatic system after injection, thus indicating its functional usefulness. (author)