Sample interview questions: Describe the principles behind laser-induced fluorescence imaging and its applications in drug discovery.
Sample answer:
Laser-induced fluorescence imaging (LIF) is a powerful imaging technique used in various fields, including drug discovery. The principles behind LIF imaging are based on the interaction of laser light with fluorescent molecules, resulting in the emission of fluorescence signals that provide valuable information.
Principles of LIF Imaging:
-
Excitation of Fluorescent Molecules: A laser is used to excite fluorescent molecules present in the sample. The laser’s wavelength is chosen to match the absorption wavelength of the fluorescent molecules, causing them to absorb the light energy and transition to an excited state.
-
Fluorescence Emission: In the excited state, the fluorescent molecules undergo a rapid transition back to the ground state, releasing the absorbed energy in the form of fluorescence photons. The emitted fluorescence photons have a longer wavelength compared to the excitation wavelength due to energy loss during the transition.
-
Detection of Fluorescence Signals: The emitted fluorescence photons are detected using a detector, such as a photomultiplier tube or a CCD camera. The detector collects and converts the fluorescence signals into electrical signals, which are then amplified and processed to generate images.
Applications of LIF Imaging in Drug Discovery:
-
Drug Screening: LIF imaging is used in high-throughput drug screening assays to identify compounds that interact with specific biological targets or cellular processes. Fluorescent molecules or probes are employed to label the targets or processes, and the interaction of drug candidates with these molecules can be visualized and quantified using LIF imaging.
-
Pharmacokinetic Studies: LIF imaging is utilized to study the pharmacokinetics of drugs, including their distribution, metabolism, and excretion. Fluorescent probes are conjugated to the drug molecul… Read full answer