C-14 Carbon-14 Labeling & Synthesis Techniques

Question 1

What is the established half-life of Carbon-14?

Accepted Answer

5,730 years

Answer

Carbon-14 has a half-life of approximately 5,730 years, which makes it valuable for radiocarbon dating and long-duration metabolic tracing studies.

Question 2

What type of radiation does Carbon-14 emit during its decay?

Accepted Answer

Low-energy beta particles

Answer

C-14 is a pure beta emitter with a maximum energy of 156.5 keV, classifying it as a low-energy beta emitter that requires liquid scintillation counting for detection.

Question 3

What does 'specific activity' mean for a C-14 labeled compound?

Accepted Answer

The amount of radioactivity per unit mass or mole (e.g., Ci/mmol or GBq/mmol)

Answer

Specific activity expresses how much radioactivity is present per unit quantity of compound, indicating what fraction of the molecules carry the C-14 label.

Question 4

In C-14 synthesis, what does 'position-specific labeling' mean?

Accepted Answer

Placing C-14 at one defined, predetermined carbon position within the molecular structure

Answer

Position-specific labeling places C-14 at an exact, known carbon atom, enabling researchers to track the metabolic fate of that specific bond or functional group.

Question 5

Which primary approach is used to introduce C-14 into organic molecules at specific positions during synthesis?

Accepted Answer

Building the molecule from C-14 labeled small-molecule precursors such as 14CO2, K14CN, or 14CH2O

Answer

C-14 labeled compounds are synthesized by incorporating C-14 labeled building blocks (such as 14CO2, K14CN, or 14CH2O) at a defined step in a classical organic synthesis sequence.

C-14 - C-14 Radioisotope Certification Practice Test

C-14 - C-14 Radioisotope Certification Practice Test

C-14 Carbon-14 Labeling & Synthesis Techniques