Tc-99m WBC Labelling

Question 1

what is used to reconstitute with the pertechnetate?

Answer 1

HMPAO

Question 2

what are the characteristics of Tc-HMPAO that allows for it to cross cell membranes?

Answer 2

its neutrality and it is lipophilic

Question 3

what prevents the Tc-HMPAO from leaving after entering the cells?

Answer 3

it converts into a hydrophilic form

Question 4

which hood is the manipulation of WBC labelling done under?

Answer 4

the biological safety cabinet

Question 5

what step is a Health Canada requirement?

Answer 5

having “clean” plasma to use for cell reinfection
- no addition of HES to 15ml amount in centrifuge tube

Question 6

what is the typical efficiency for WBC labelling?

Answer 6

40-80%

Question 7

how do you kill off the RBC that remain even after settling?

Answer 7

addition of water to make the concentration higher in the cell vs. outside the cell leading water to go into the cells and lysing.

Question 8

how do you limit damage to WBCs?

Answer 8

• using a large bore needle and draw slowly
• low speeds of centrifugation with samples with the WBCs

Question 9

what is the time frame that you should inject your patients with the labelled WBCs?

Answer 9

1-2 hrs after labeling to maintain viability

Question 10

what is the labelling alternative for WBCs?

Answer 10

In-111-oxine

Question 11

anything entering the biological safety cabinet must be sterilized. t/f

Answer 11

true