CLINICAL CHEMISTRY Flashcards
(42 cards)
1
Q
- Which of the following lamps provides a continuous spectrum of radiant energy in the visible, near IR, and near UV regions of the spectrum?
A. Tungsten-filament
B. Hydrogen
C. Deuterium
D. Mercury vapor
A
2
Q
- Which of the following isolates light within a narrow region of the spectrum?
A. Photomultiplier tube
B. Monochromator
C. Photovoltaic cell
D. Detector
A
3
Q
- Which of the following is not descriptive of a photomultiplier tube?
A. Emits electrons proportionally to initial light absorbed
B. Must be shielded from stray light
C. Cannot be used with a chopper
D. Amplifies the initial signal received
A
4
Q
- Which of the following is false about a photomultiplier tube?
A. Converts radiant energy (light)
to electrical energy (current)
B. Amplifies the current significantly
C. Has a very rapid response time
D. Is composed of an iron plate and a layer of selenium
A
5
Q
- Which type of photodetector employs a linear arrangement that allows it to respond to a specific wavelength resulting in complete UV/visible spectrum analysis?
A. Photomultiplier tube
B. Phototube
C. Barrier layer cell
D. Photodiode array
A
6
Q
- When performing spectrophotometer quality assurance checks, what is the holmium oxide glass filter used to assess?
A. Linearity
B. Stray light
C. Absorbance accuracy
D. Wavelength accuracy
A
7
Q
- In spectrophotometric analysis, what is the purpose of the reagent blank?
A. Correct for interfering chromogens
B. Correct for lipemia
C. Correct for protein
D. Correct for color contribution of the reagents
A
8
Q
- In regard to bichromatic analysis, which of the following is false?
A. Absorbance is measured at the spectral absorbance peak for a blank and the sample using the same wavelength.
B. Eliminates background interferences
C. Sample concentration determined from difference in two measured absorbances
D. Functions as a reference blank for each sample
A
9
Q
- The bandpass of a spectrophotometer is 10 nm. If an instalment is set at 540 nm, the wavelengths that are permitted to impinge on the sample will be within what wavelength range?
A. 530-540 nm
B. 530-550 nm
C. 535-545 nm
D. 540-550 nm
A
10
Q
- Which of the following formulas is an expression of the Beer Lambert law that is routinely applied to spectrophotometric analysis?
A. Au * (Cs/As) = Cu
B. Cu * (Cs/As) = Au
C. As * (Cs/Cu) = Au
D. A = 2 - log %T
A
11
Q
- In spectrophotometry, which of the following is a mathematical expression of the relationship between absorbance and transmittance?
A. A = abc
B. (Au/Cu) = (As/Cs)
C. A = 2 - log %T
D. A = log %T
A
12
Q
- Which of the following is not a problem inherent in turbidimetry?
A. Variation in particle size of samples
B. Variation in particle size of standards
C. Rate of aggregation or settling of particles
D. Need to maintain a constant and specific temperature
A
13
Q
- Which of the following may be associated with reflectance spectrophotometry as it relates to the dry reagent slide technique?
A. Light projected to the slide at 180-degree angle
B. Dye concentration directly proportional to reflectance
C. Unabsorbed, reflected light detected by photodetector
D. Reflectance values are linearly proportional to transmission values
A
14
Q
- Fluorometers are designed so that the path of the exciting light is at a right angle to the path of the emitted light. What is the purpose of this design?
A. Prevent loss of emitted light
B. Prevent loss of the excitation light
C. Focus emitted and excitation light upon the detector
D. Prevent excitation light from reaching the detector
A
15
Q
- Which of the following represents a primary advantage of performing fluorometric over absorption spectroscopic methods of analysis?
A. Increased specificity and increased sensitivity
B. Increased specificity and decreased sensitivity
C. Purity of reagents used not as critical
D. Ease of performing assays
A
16
Q
- Which of the following may be associated with fluorescence polarization?
A. Plane-polarized light is used for sample excitation.
B. Small molecular complexes show a greater amount of polarization.
C. It is a heterogeneous technique employed in fluorophore-ligand immunoassays.
D. Polarized light detected is directly proportional to concentration of ligand in sample.
A
17
Q
- Which of the following may be associated with bioluminescence?
A. Light emission produced due to enzymatic oxidation of a substrate
B. Less sensitive than direct fluorescent assays
C. Electron excitation caused by radiant energy
D. Employs a radioactive label
A
18
Q
- Nephelometry is based on the measurement of light that is
A. Absorbed by particles in suspension
B. Scattered by particles in suspension
C. Produced by fluorescence
D. Produced by excitation of ground-state atoms
A
19
Q
- Which of the following instruments is used in the clinical laboratory or in reference laboratories to detect beta and gamma emissions?
A. Fluorometer
B. Nephelometer
C. Scintillation counter
D. Spectrophotometer
A
20
Q
- Which of the following best describes chemiluminescence?
A. Electron excitation caused by radiant energy
B. Enzymatic oxidation of a substrate produces light emission
C. Chemical energy excites electrons that emit light upon return to ground state
D. Employs a fluorescent label that produces light
A
21
Q
- In assaying an analyte with a single-beam atomic absorption spectrophotometer, what is the instrument actually measuring?
A. Intensity of light emitted by the analyte on its return to the ground state
B. Intensity of light that the analyte absorbs from the hollow-cathode lamp
C. Intensity of light that the analyte absorbs from the flame
D. Intensity of the beam from the hollow-cathode lamp after it has passed through the analyte-containing flame
A
22
Q
- What is the function of the flame in atomic
absorption spectroscopy?
A. Absorb the energy emitted from the metal analyte in returning to ground state
B. Supply the thermal energy needed to excite the metal analyte
C. Bring the metal analyte to its ground state
D. Supply the light that is absorbed by the metal analyte
A
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