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Clinical Chem 1
Success! Clinical Laboratory Science
Question | Answer |
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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 | Tungsten-filament |
Which of the following isolates light within a narrow region of the spectrum? A. Photomultiplier tube B. Monochromator C. Photovoltaic cell D. Detector | Monochromator |
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 | Cannot be used with a chopper |
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 anda layer of selen | Is composed of an iron plate and a layer of selenium |
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? | 535-545 nm |
Which of the following formulas is an expression of the Beer-Lambert law that is routinely applied to spectrophotometric analysis? | Au x Cs/As=Cu |
In spectrophotometry, which of the following is a mathematical expression of the relationship between absorbance and transmittance? | A = 2 - log %T |
Which of the following may be associated with reflectance spectrophotometry as it relates to the dry reagent slide technique? | Unabsorbed, reflected light detected by photodetector |
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? | Prevent excitation light from reaching the detector |
Which of the following represents a primary advantage of performing fluorometric over absorption spectroscopic methods of analysis? | Increased specificity and increased sensitivity |
Which of the following may be associated with fluorescence polarization? | Plane-polarized light is used for sample excitation. |
Which of the following may be associated with bioluminescence? | Light emission produced due to enzymatic oxidation of a substrate |
Nephelometry is based on the measurement of light that is | Scattered by particles in suspension |
Which of the following instruments is used in the clinical laboratory or in reference laboratories to detect beta and gamma emissions? | Scintillation counter |
Which of the following best describes chemiluminescence? | Chemical energy excites electrons that emit light upon return to ground state |
In assaying an analyte with a single-beam atomic absoiption spectrophotometer, what is the instrument actually measuring? | Intensity of the beam from the hollowcathode lamp after it has passed through the analyte-containing flame |
What is the function of the flame in atomic absorption spectroscopy? | Bring the metal analyte to its ground state |
Most atomic absorption spectrophotometers incorporate a beam chopper and a tuned amplifier. The purpose of these components is to avoid errors that would be caused by | Measurement of light emitted by the analyte |
In potentiometry, which of the following is considered the standard electrode? | Hydrogen electrode |
In an electrolytic cell, which of the following is the half-cell where reduction takes place? | Cathode |
Mercury covered by a layer of mercurous chloride in contact with saturated potassium chloride solution is a description of which of the following types of electrodes? | Calomel |
When a pH-sensitive glass electrode is not actively in use, in what type of solution should it be kept? | The medium recommended by the manufacturer |
When measuring K+ with an ion-selective electrode by means of a liquid ionexchange membrane, what antibiotic will be incorporated into the membrane? | Valinomycin |
What are the principles of operation for a chloride analyzer that generates silver ions as part of its reaction mechanism? | Amperometry and coulometry |
When quantifying glucose using an amperometric glucose electrode system, which of the following is not a component of the system? | Hexokinase reacts with glucose |
To calibrate the pH electrode in a pH/ blood gas analyzer, it is necessary that | Two buffer solutions of known pH be used |
The measurement of CO2 in blood by means of a PCO2 electrode is dependent on the | Change in pH because of increased carbonic acid in the electrolyte surrounding the electrodes |
The measurement of oxygen in blood by means of a PO2 electrode involves which of the following? | Direct relationship between amount of oxygen in the sample and amount of current flowing in the measuring system |
Which of the following blood gas parameters are measured directly by the blood gas analyzer electrochemically as opposed to being calculated by the instrument? | pH, PCO2, PO2 |
Which of the following methods allows for the separation of charged particles based on their rates of migration in an electric field? | Electrophoresis |
Which of the following techniques is based on electro-osmotic flow? | Capillary electrophoresis |
In serum protein electrophoresis, when a buffer solution of pH 8.6 is used, which of the following characterizes the proteins? | Exhibit net negative charge |
Which of the following characteristics will a protein have at its isoelectric point? | Net zero charge |
What dye may be used for staining protein bands following electrophoresis? | Ponceau S |
When electrophoresis is performed, holes appear in the staining pattern, giving the stained protein band a doughnut-like appearance. What is the probable cause of this problem? | Protein concentration was too high |
What is the purpose of using ampholytes in isoelectric focusing? | Establish a pH gradient in the gel |
Which of the following is not associated with silver stains? A. Reactive to nanogram concentrations of proteins B. Polypeptides stain a variety of colors C. Not as sensitive as Coomassie brilliant blue D. Preconcentration of CSF not necessary | Not as sensitive as Coomassie brilliant blue |
Which of the following is not associated with isoelectric focusing? A. Continuous pH gradient B. Migration of proteins with net charge of zero C. Separation dependent on isoelectric point D. Zone electrophoresis | Migration of proteins with net charge of zero |
Which of the following is an electrophoretic technique employing a pH gradient that separates molecules with similar isoelectric points? | Isoelectric focusing |
To achieve the best levels of sensitivity and specificity, to what type of detector system could a gas chromatograph be coupled? | Mass spectrometer |
Which of the following instruments has a sample-introduction system, solventdelivery system, column, and detector as components? | High-performance liquid chromatograph |
Which type of elution technique may be used in high-performance liquid chromatography? | Gradient |
Which of the following statements best describes discrete analysis? | Each sample-reagent mixture is handled separately in its own reaction vessel. |
Which of the following chromatography systems may be described as having a stationary phase that is liquid absorbed on particles packed in a column and a liquid moving phase that is pumped through a column? | High-performance liquid |
Which of the following chromatography systems is characterized by a stationary phase of silica gel on a piece of glass and a moving phase of liquid? | Thin-layer |
Ion-exchange chromatography separates solutes in a sample based on the | Sign and magnitude of the ionic charge |
Which parameter is used in mass spectrometry to identify a compound? | Ion mass-to-charge ratio |
Which chromatography system is commonly used in conjunction with mass spectrometry? | Gas-liquid |
Which of the following may be a sampling source of error for an automated instrument? | Short sample, Air bubble in bottom of sample cup, Fibrin clot in sample probe |
Checking instrument calibration, temperature accuracy, and electronic parameters are part of | Function verification |
Which globin chains compose hemoglobin A1? | Two alpha chains and two beta chains |
Which hemoglobin may be differentiated from other hemoglobins on the basis of its resistance to denature in alkaline solution? | F |
Hemoglobin S is an abnormal hemoglobin that is characterized by a substitution of which amino acid? | Valine for glutamic acid in position 6 on the beta chain |
When performing electrophoresis at pH 8.6, which hemoglobin molecule migrates the fastest on cellulose acetate toward the anode? | A1 |
Because of similar electrophoretic mobilities, several hemoglobins cannot be differentiated on cellulose acetate medium. Electrophoresis of hemoglobins at pH 6.2 on agar gel may be useful in differentiating which hemoglobins? | C from A2 |
In addition to performing hemoglobin electrophoresis, a solubility test may be performed to detect the presence of what hemoglobin? | S |
Which of the following is not quantified using an immunoassay method? | Electrolytes |
Which of the following is a homogeneous immunoassay where separation of the bound from the free labeled species is not required? | Enzyme-multiplied immunoassay technique (EMIT) |
When using EMIT, the enzyme is coupled to | Antigen |
The enzyme activity measured in the EMIT is the result of the reaction between the substrate and coenzyme with | Free labeled antigen |
Singlet oxygen reacting with a precursor chemiluminescent compound to form a decay product whose light energizes a fluorophore best describes | Luminescent oxygen channeling immunoassay |
Which of the following stimulates the production of singlet oxygen at the surface of the sensitizer particle in a luminescent oxygen channeling immunoassay? | Radiant energy |
Proteins, carbohydrates, and lipids are the three major biochemical compounds of human metabolism. What is the element that distinguishes proteins from carbohydrate and lipid compounds? | Nitrogen |
Proteins may become denatured when subjected to mechanical agitation, heat, or extreme chemical treatment. How are proteins affected by denaturation? | Alteration in tertiary structure |
What is the basis for the Kjeldahl technique for the determination of serum total protein? | Quantification of the nitrogen content of protein |
When quantifying serum total proteins, upon what is the intensity of the color produced in the biuret reaction dependent? | Number of peptide bonds |
Which of the following reagents can be used to measure protein in cerebrospinal fluid? | Coomassie brilliant blue |
Which disorder is not associated with an elevated protein level in cerebrospinal fluid? | Hyperthyroidism |
Which term describes a congenital disorder that is characterized by a split in the albumin band when serum is subjected to electrophoresis? | Bisalbuminemia |