Lab Modules 1-6

Question 1

Principle of kohler illumination

Answer 1

Align components to provide even illumination

Match the numerical aperture of the condenser to that of the objective lens - provides best resolution

Question 2

Calibration curve title includes:

Answer 2

Analyte
Method
Instrument name and number
Wavelength
Date
Technologist

Question 3

What does Beer’s Law state

Answer 3

Absorbance is directly proportional to concentration

Question 4

Purpose of a reagent blank

Answer 4

Accounts for A due to original colour of reagents

Question 5

Principle of flame photometry

Answer 5

Certain elements emit characteristic wavelengths when heated in a flame that allows for quantitation in clinical samples

Question 6

Most common elements measured in flame photometry

Answer 6

Sodium, potassium, lithium

Question 7

In flame photometry, Na is measured at what wavelength?

Answer 7

589 nm

Question 8

In flame photometry, K is measured at what wavelength?

Answer 8

766 nm

Question 9

In flame photometry, Li is measured at what wavelength?

Answer 9

670 nm

Question 10

Major components of the flame photometer

Answer 10

Atomizer/burner, wavelength selector, photodetector, processor, display

Question 11

What is the internal standard used in the flame photometer?

Answer 11

Cesium

Question 12

What is the fuel-oxidant combination used in the flame photometer?

Answer 12

Propane and compressed air

Question 13

What is the purpose of internal standard?

Answer 13

Account for variations in the system

Question 14

What is osmolality

Answer 14

Number of osmoles/kg solvent

Question 15

What are osmoles

Answer 15

osmoles = moles x # of particles into which the molecule dissociates
example: NaCl -> Na + Cl (2 particles)
1 mole NaCl x 2 = 2 osmoles

Question 16

How does an osmometer determine the concentration of solutions?

Answer 16

Measures the freezing point depression and converts it to mOsm/kg H2O

Question 17

Measured osmolality

Answer 17

Determined by analytical means, usually by freezing point depression

Question 18

Calculated osmolality

Answer 18

Indirect

Determined by using concentrations of the main osmotically active substances (sodium, glucose, urea)

Question 19

Calculated osmolality formula

Answer 19

= 1.86 [Na] + [Glucose] + [Urea] + 9

Question 20

Osmolal gap

Answer 20

The difference between the measured and calculated osmolality
Can reflect the presence of other osmotically active substances such as volatiles
Osm gap = measured - calculated

Question 21

Unaccounted osmolal gap

Answer 21

The difference between the measured and calculated osmolality plus the concentration of ethanol
Can reflect the presence of volatiles other than ethanol
Unaccounted = measured - (calculated + ethanol)

Question 22

Basic principles of vitros instrument operation

Answer 22

Slide identification
Slide spotting
Incubation
Read reflectance of coloured end product
Calculate and print results

Question 23

What type of photometer is the Vitros DT 60?

Answer 23

Refectance

Question 24

The layer of the Vitros slide which distributes serum evenly, traps interfering proteins, and reflects light is:

Answer 24

Spreading layer

Question 25

What is used to measure potential in a Vitros photometer?

Answer 25

Electrometer (voltmeter)

Question 26

4 electrolytes that can be determined in the DTE:

Answer 26

Na, K, Cl, CO2

Question 27

On the Ektachem slide, the ion selective membrane functions to:

Answer 27

Select the electrolyte to pass through to the reference layer

Question 28

On the Ektachem slide, the reference electrode:

Answer 28

Has a constant potential

Question 29

On the Ektachem slide, the measuring electrode:

Answer 29

Has a variable potential proportional to the electrolyte