advance topics lab operations

The volume of 25% stock sulfosalicylic acid needed to prepare one 100 mL of 5% working solution is:

5 mL

20 ml

50 mL

1.25 mL

20 ml

Which of the following is the main responsibility of the Occupational Safety and Health Administration (OSHA)?

To regulate the prices of personal protective equipment (PPE)

To set and enforce workplace safety standards to protect employees

To provide financial support for healthcare facilities

To manage employee health insurance plans

To set and enforce workplace safety standards to protect employees 🛡️

The use of security systems such as firewalls and data encryption for electronic transmission of patient data from laboratory information system to a remote location are required for

ICD-9

LOINC

CLIA

HIPAA

HIPAA (Health Insurance Portability and Accountability Act) regula la seguridad y privacidad de la información del paciente.

On electrophoresis, distorted zones of protein separation are usually due to

pre staining with tracer dye

Presence of therapeutic drugs in serum sample

Dirty applicators

Overloading of serum sample

Overloading of serum sample ⚡

Given the following data, calculate the coefficient of variation for glucose:

Mean 76 mg\dL

Standard deviation 2.3

7.6%

3%

33%

4.6%

3%

Absorbance of a solution may be converted to percent transmittance using the formula

1-log%T

2+log%T

1+log%T

2-log%T

2 − log %T

Use of "standard" (universal) precautions minimizes exposure to

Radiation hazards

Chemical hazards

Bloodborne pathogens

Environmental hazards

Bloodborne pathogens

The middle value of a data set is statistically known as the:

Mode

Median

Mean

Standard deviation

Median

In flow cytometry, labeled cells:

absorb fluorescence and emit electronic impulses

absorb both fluorescence and light

scatter the light and emit fluorescence

scatter the light and absorb fluorescence

scatter the light and emit fluorescence

A Delta check is a method that

Is determined by each laboratory facility

Monitors patient samples day to day

Determines the mean and variance of an instrument

Monitors the testing system for precision

Monitors patient samples day to day

Examine the Levy-Jennings chart. Identify the QC problem that occurred during the first half of the month.

trend

shift

random error

Kurtosis

Which of the following require laboratories to establish a chemical hygiene plan?

CAP (College of American pathologists)

ACS (American Chemical Society)

CLIA (clinical laboratory Improvement Act)

OSHA (Occupational Safety and Health Act)

OSHA (Occupational Safety and Health Act)

Pre analytical (pre-examination) variables in laboratory testing include:

Report delivery to the ordering physician

Test turn around time

Result accuracy

Specimen acceptability

Specimen acceptability

A mass spectrometer detects which property of ionized molecules?

Mass to charge ratio

Fluorescence

Column retention time

Charge to mass ratio

Mass to charge ratio (m/z)

A solution contains 20 g of solute dissolved in 0.5 L of water. What is the percentage of the solution?

8%

2%

6%

4%

4%

When 0.25 mL is diluted to 20 mL, the resulting dilution is:

1:80

1:60

1:40

1:20

1:80

When referring to quality control results, what parameter usually determines the acceptable range?

The range encompassed by + 2.5 standard deviations

The range that includes 50% of the results

The 95% confidence interval for the mean

The central 68% of results

The 95% confidence interval for the mean

Hepatitis B vaccine is

Recommended only when an exposure incident occurs

Required for all health care employees

Must be provided by the employer free of charge

Administered as a single one time injection

Must be provided by the employer free of charge

How many milliliters of glacial acetic acid are needed to prepare 2.0L of 10% acetic acid?

100.0 milliliters

10.0 milliliters

20.0 milliliters

200.0 milliliters

200.0 milliliters

After receiving appropriate training, the first step in using a fire extinguisher is to

aim the hose at the base of the fire

Sweep the flow of the hose from side to side

Squeeze the top handle or lever

Pull the pin

Pull the pin

How many mL of 30% bovine albumin are needed to make 6 mL of 10% albumin solution?

4 mL

1 mL

2 mL

3 mL

2ml

In spectrophotometry, the device that allows a narrow band of wavelength is the:

Photodetector

Refractometer

Monochromator

Hollow cathode lamp

Monochromato

Which of the following is not a potential source of post analytical (post examination) errors?

Excessive delay in reporting or retrieving a test result

Verbal notification of test result

Labeling the specimen at the nurses station

Interpretation of result

Labeling the specimen at the nurses station

In Electrophoretic analysis, buffers:

Produce an effect on protein configuration

Act as a carrier for ions

Maintain basic pH

Stabilize electrolytes

Act as a carrier for ions

Referring to the Levy Jennings chart, what is the first day in the month when the run should be rejected and patient results should be repeated using conventional QC limits and multirules?

Day 9

, Not Selected

Day 6

, Not Selected

Day 8

, Not Selected

Day 7

Which of the following agencies uniformly regulates the packaging and shipping of specimens and dangerous goods?

Department of Transportation (DOT)

International Air Transport Association (IATA)

DOT, IATA, and USPS have different rules regarding shipping of biologic specimens and infectious materials

United States Postal Service (USPS)

DOT, IATA, and USPS have different rules regarding shipping of biologic specimens and infectious materials

Medicare and Medicaid Services (CMS) with established in the Social Security Act of 1965. Which of these statements related to CMS payment for laboratory service is true?

Medicare part a (inpatient coverage closed parentheses and Part B (outpatient coverage closed parentheses includes prescription drug coverage

Medicaid is administered by the federal government

Laboratories must have a current CLIA certificate to submit claims to Medicare or Medicaid

Medicare provides medical coverage to individual 65 and older at no cost to the individual

Laboratories must have a current CLIA certificate to submit claims to Medicare or Medicaid ✅

The safest method for disposing of hypodermic needles is:

Cut the needle with a special device before disposal

Drop the needle in the wastebasket immediately after use

Recap the needle with its protective sheath prior to discarding

Discard the needle in an impermeable container without other handling immediately after use

Discard the needle in an impermeable container without other handling immediately after use

Which technique is used to detect DNA containing a specific base sequence by applying a labeled probe to DNA bands immobilized onto nitrocellulose paper after electrophoresis?

Dot blot

Western blot

Northern blot

Southern blot

Southern blot

What is the primary purpose of laboratory proficiency testing?

To train personnel on laboratory equipment usage

To develop new testing methods for laboratory use

To evaluate the laboratory's ability to produce accurate and reliable results

To ensure compliance with workplace safety regulations

To evaluate the laboratory's ability to produce accurate and reliable results

Nephelometers measure light:

Reflect back to the source from opaque suspensions

Transmitted by now particulate mixtures

Absorbed by suspended particles

Scattered at a right angle to the light path

Scattered at a right angle to the light path

Using conventional QC rules, which of the following conditions is cause for rejecting an analytical run?

4 controls steadily increasing in value but less than + 1s from the mean

One control above +1s and the other below -1s from the mean

Two consecutive controls greater than 2s above or below the mean

Three consecutive controls greater than 1s above the mean

Two consecutive controls greater than 2s above or below the mean

Test precision is verified by

Comparing results of multiple specimens analyzed by multiple individuals and multiple instrument

Comparing results to a definitive or reference method for the same analyte

Comparing results from analyzing the same specimen on multiple analyzers over time

Repeat measurements of samples of multiple concentrations within run and between runs performed over a period of time

Repeat measurements of samples of multiple concentrations within run and between runs performed over a period of time

What are the three steps of an individualized quality control plan (IQCP)?

Risk assessment, quality control plan, quality assessment

Quality control plan, quality assessment, and quality improvement

Assessment of pre analytical, analytical, and post analytical errors

Inventory management, instrument selection, quality control plan

Risk assessment, quality control plan, quality assessment

Class C fire involves

Electrical equipment

Paper, wood and plastics

Xylene and alcohol

Grease and oil

Class C: Electrical equipment — wiring, panels, appliances

Which disinfectant inactivates HIV and HBV?

Alcohol

Iodine

Sodium hypochlorite

phenol

Sodium hypochlorite

Which of the following is the best practice for storing flammable solvents in a laboratory?

Store flammable solvents in open containers to allow for ventilation

Store flammable solvents in regular cabinets with no special ventilation

Store flammable solvents in a flammable liquids storage cabinet with proper labeling and ventilation

Store flammable solvents in non-metallic containers in a cool, dry area away from heat sources

Store flammable solvents in a flammable liquids storage cabinet with proper labeling and ventilation ✅

One means of checking a spectrophotometer wavelength calibration in the visible range is by using a:

Quartz prism

Quartz filter

Defraction grating

didymium filter

Didymium filter

In quality control, + 2 Standard deviations from the Mean include what percentage of the sample population? 

50%

75%

98%

95%

95%

How many mL have red blood cells are to be used to make 25mL of 4% red cell suspension?

1mL

0.25mL

0.5mL

2mL

1ml

Which of the following is the formula for standard deviation?

square root of (mean)/(sum of squared differences)

square root of the mean

square root of (sum of the squared differences from the mean)/(N-1)

square root of the variance

Square root of (sum of the squared differences from the mean)/(N-1) ✅

What is the primary purpose of the Clinical Laboratory Improvement Amendments (CLIA) of 1988?

To regulate the pricing of medical tests and laboratory equipment

To ensure the accuracy, reliability, and timeliness of patient test results in clinical laboratories

To provide funding for laboratory research in healthcare

To standardize the procedures for medical billing and coding

To ensure the accuracy, reliability, and timeliness of patient test results in clinical laboratories

Given this set of values

100, 120, 150, 140, 130

What is the mean?

130

640

100

128

128

What is the single most effective method to prevent nosocomial spread of infection?

Require infectious patients to mask

Perform frequent and appropriate hand hygiene

Wear mask, gown and gloves

Wear an N95 respirator mask

Perform frequent and appropriate hand hygiene

Which of the following statistical tests is used to compare the means of two methods?

T-test

Correlation coefficient

Linear regression analysis

F-test

T-test

Which of the following is the formula for calculating the dilution of a solution?

V1+C1=V2+C2

V1C1=V2C2

V1V2=C1C2

V1+C2=V2+C1

V₁ × C₁ = V₂ × C₂

Which of the following is NOT typically found in a Safety Data Sheet (SDS)?

Information about the chemical’s physical and chemical properties

Instructions for proper disposal of the chemical

First aid measures in case of exposure to the chemical

Detailed instructions for the chemical's production and manufacturing process

Detailed instructions for the chemical's production and manufacturing process

Clinical laboratory improvement amendments of 1988 (CLIA) was established to provide oversight to:

Waived point of care testing by non-laboratory personnel

All US facilities or sites performing patient testing to diagnose, prevent, or treat disease

Research labs performing testing on human specimens

CAP accredited labs

All US facilities or sites performing patient testing to diagnose, prevent, or treat disease

Which of the following statements is true regarding the process of electrophoresis?

In electrophoresis, larger molecules move faster through the gel compared to smaller molecules.

Only proteins can be separated using electrophoresis, not nucleic acids.

The molecules in an electrophoresis gel move from the positive electrode to the negative electrode.

Electrophoresis is used to separate molecules based on their size and charge by applying an electric field.

Electrophoresis is used to separate molecules based on their size and charge by applying an electric field.

An example of personal protective equipment (PPE) is:

A lab coat

An eye-wash station

An emergency safety shower

A biological safety cabinet

A lab coat

When processing specimens from mycobacterial testing, what specific engineering control must be used?

Biological safety cabinet

fume hood

Barrier protection only

Horizontal laminer flow hood

Biological safety cabinet

How does a Youden plot help in quality control analysis?

By calculating the standard deviation of repeated measurements

By plotting the distribution of random errors over time

By comparing the precision of different testing instruments

By identifying systematic errors between two laboratories or methods

By identifying systematic errors between two laboratories or method

The extent to which measurements agree with the true value of the quantity being measured is known as

Reliability

Accuracy

Reproducibility

Precision

Accuracy

Which of the following correctly pairs a purine with its complementary pyrimidine base in DNA?

Cytosine (C) pairs with Thymine (T)

Adenine (A) pairs with Cytosine (C)

Adenine (A) pairs with Thymine (T)

Guanine (G) pairs with Uracil (U)

Adenine (A) pairs with Thymine (T

The most frequent value in a collection of data is statistically known as

Standard deviation

mean

Mode

Mode

Osmometry is a technique for measuring the concentration of solute particles that contribute to the osmotic pressure of a solution. The most common method used in the clinical laboratory to measure osmolarity is

Dew point pressure

Freezing point depression

Boiling point

osmotic pressure

Freezing point depression

A mean value of 100 in a standard deviation of 1.8 mg/dL Are obtained from a set of glucose measurements on a control solution. The 95% confidence interval in mg/dL would be:

98.2-101.8

96.4-103.6

94.6-105.4

97.3-102.7

96.4-103.6 mg/dL

Which of the following is the best choice for decontaminating bench tops contaminated by the AIDS virus?

Formalin

100% alcohol

Sodium hypochlorite bleach

A quaternary ammonium compound

Sodium hypochlorite bleach

The term used to describe reproducibility is:

Precision

Sensitivity

Accuracy

Specificity

Precision

Which of the following statements about fluorometry is true

Fluorometry is less sensitive than spectrophotometry

The detector in a florometer is positioned at 180 degrees from the excitation source

A compound fluorescence when it absorbs life at one wavelength and admits light at a 2nd wavelength

An incandescent lamp is commonly used in fluorometer

A compound fluoresces when it absorbs light at one wavelength and emits light at a second wavelength

Which of the following statements about fluorochromes is false?

Fluorochromes are commonly used in immunofluorescence to visualize specific molecules in biological samples.

The emission wavelength of a fluorochrome is longer than its excitation wavelength.

Fluorochromes are molecules that emit fluorescence when excited by light of a specific wavelength.

Fluorochromes can only be used in ultraviolet light microscopy, not in visible light.

Fluorochromes can only be used in ultraviolet light microscopy, not in visible light.

The target in the figure illustrates a set of results that show a high degree of

Accuracy

Specificity

Precision

Sensitivity

Precisison

Gloves worn in the laboratory for specimen processing must be removed and hands-washed when

Answering the telephone in a designated "clean" area

Carrying a specimen outside the technical work area through "clean" areas

Answering the telephone in the technical work area

After handling specimens from known isolation precaution patients

Carrying a specimen outside the technical work area through "clean" areas

Diagnostic specificity is defined as the percentage of individuals

With a given disease who have a positive result by a given test

Without a given disease who have a positive result by a given test

With a given disease who have a negative result by a given test

Without a given disease who have a negative result by a given test

Without a given disease who have a negative result by a given test

Chromatography is based on the principle of

Gravity

Temperature

Vapor pressure

Differential solubility

Differential solubility

A technologist spilled 10 gallons of formaldehyde on the floor. After determining the chemicals poses a significant health hazard, the first action step would be to

Don appropriate personal protective equipment

Evacuate the area

Notify emergency assistance

Control the spill with appropriate absorbent material

Evacuate the area

Which of the following best describes random error in quality control testing?

An unpredictable variation that occurs due to chance during measurements

An error that arises from using an incorrect method of analysis

A consistent bias introduced by faulty equipment or procedures

A deviation caused by systematic changes in environmental conditions

An unpredictable variation that occurs due to chance during measurements

This symbol indicates which of the following hazards?

Biohazard

Flammable

Radiation

Electrical

Flammable

A hematology analyzer counts red cells by which method?

turbidimetric

Photometric

Chromogenic

Impedance

Impedance

PCR involves three processes. Select the order in which these occur.

Denaturation-->Annealing--> Extension

, Not Selected

Extension-->Annealing-->Denaturation

, Not Selected

Annealing--> Denaturation--> Extension

, Not Selected

Denaturation--> Extension-->Annealing

Denaturation → Annealing → Extension

In the context of DNA structure, which of the following correctly describes the orientation of the two strands of a DNA double helix?

Both strands run in the 3' to 3' direction.

The strands run parallel to each other in the same direction.

The two strands run in opposite directions, with one strand oriented 5' to 3' and the other 3' to 5'.

The two strands run in the same direction (5' to 5' and 3' to 3').

The two strands run in opposite directions, with one strand oriented 5' to 3' and the other 3' to 5'.

Which of the following is the formula for calculating a percent (w/v) solution?

(grams of solute * volume of solvent)/100

grams of solute/ volume of solvent * 100

volume of solvent/ grams of solute *100

grams of solute volume of solvent 100

grams of solute / volume of solvent * 100

Given the following QC data chart, identify the day in which a violation of the R4S rule occurs:

Day 3

, Not Selected

Day 10

, Not Selected

Day 15

, Not Selected

Day 8

day 10 o 15

A Levy-Jennings quality control chart is shown, which represents control values for 13 consecutive analyses for a particular serum constituent. If the 14th value is below the -2SD Limit, which of the following should be done?

Analysis system should be checked for a change in reagent lot number

No action is needed

Control should be repeated to see if it will fall within the established interval

,

Analysis system should be checked for deteriorating component

Analysis system should be checked for deteriorating component

This symbol represents:

An environmental hazard

A biohazard

A chemical hazard

A radiation hazard

biological hazard