CELL LABELING

• There are important indications for performing imaging procedures with cell labeled radiopharmaceuticals. There are special handling and anticoagulation techniques required to achieve optimal labeling.

• There are three methods of labeling Red Blood Cells-RBC with Tc-99m. All are simple, rapid, inexpensive and reliable. It is important to compare the advantages and disadvantages of each, and predict the labeling efficiencies obtained with each method.

  • Invivo / Invivo

  • Invivo / Invitro

  • Invitro / Invitro

• Other labeling protocols involve White Blood Cells, Cromium 51 and platelets.

  • Cr-51 RBC's

    • It is very easy to label red cells with Cr-51.
       

    • Isolation of RBCs is not required.
      

  • Tc-99m WBC's
    

  • In-111 WBC's

    • It is easy to label White Blood Cells- WBCs with either Tc-99m or In-111. 
      

    • Both preparations involve isolation of the WBCs and incubation with a lipophilic intermediate to effect labeling.
      

  • In-111 platelets
    

• There are special cases such as GI Bleeding studies or hemangioma localization. GI Bleeding studies are optimally performed with Tc-99m RBCs prepared using the packed cell technique or the UltraTag kit.

• Most labeling procedures can be performed in any laboratory by a person knowledgeable about aseptic technique.