Question 1

Which series of dilutions would be best in order to make a 1:3000 dilution?&#10;A) 1:10,1:3,1:10&#10;B) 1:5,1:6,1:100&#10;C) 1:3,1:100,1:100&#10;D) 1:30,1:10,1:100

Accepted Answer

1:5,1:6,1:100

Question 2

If 0.9 mL of saline is added to 0.1 mL of serum,what does the 0.9 mL represent?&#10;A) the final dilution&#10;B) the diluent&#10;C) the solute&#10;D) the total solution

Accepted Answer

0.9 mL represents the diluent, or the solution added to the serum to create a dilution. The solute in this case is the 0.1 mL of serum. The total solution would be the combination of both the diluent and the solute. However, the question specifically asks what the 0.9 mL represents, and that is the diluent. Therefore, the best answer is B.

Question 3

Information on any potentially toxic substance used in a laboratory test kit would be found in:&#10;A) OSHA's Occupational Exposure to Bloodborne Pathogens Standard&#10;B) chemical hygiene plan&#10;C) material safety data sheet&#10;D) exposure control plan

Accepted Answer

Material safety data sheets (MSDS) contain all the necessary information about potentially hazardous chemicals, including their toxicity, physical properties, protective measures, and emergency procedures. This information is required by law under the Occupational Safety and Health Administration's (OSHA) Hazard Communication Standard to ensure that workers are adequately informed and protected when working with hazardous chemicals.

Question 4

Use of universal precautions is best explained by which of the following?&#10;A) handling a urine specimen from a patient with a bacterial infection very carefully&#10;B) wearing gloves in handling a serum specimen from a patient with HIV&#10;C) taking gloves off in the lab to place a serum specimen in a chemistry analyzer&#10;D) treating every specimen in the lab as if it were infectious

Accepted Answer

Universal precautions require that all specimens be treated as if they are infectious, regardless of known or suspected infection status. This ensures the safety of healthcare workers and the public by minimizing the risk of transmission of bloodborne and other infectious diseases. Handling a specific specimen with care (A), wearing gloves for specific specimens (B), or removing gloves (C) does not encompass the comprehensive approach of universal precautions.

Question 5

If you want to make 4 mL of a 1:20 dilution,how much serum would be needed?&#10;A) 0.2 mL&#10;B) 2 mL&#10;C) 0.5 mL&#10;D) 1 mL

Accepted Answer

A 1:20 dilution means 1 part serum to 19 parts diluent, making a total of 20 parts. For 4 mL total volume, the amount of serum needed is $4 mL \times \frac{1}{20} = 0.2 mL$.

Question 6

On a serial dilution with the following tubes set up,1:2,1:4,1:8,1:16,1:32,and 1:64,there is no visible agglutination in the 1:64 tube.What is the titer of the antibody?&#10;A) 32&#10;B) 16&#10;C) 64&#10;D) cannot determine

Accepted Answer

The titer of the antibody is the highest dilution at which agglutination is still visible. Since there is no agglutination in the 1:64 tube, the highest dilution with visible agglutination is 1:32.

Question 7

When 0.5 mL of serum is added to 1.5 mL of diluent,what dilution does this represent?&#10;A) 1:3&#10;B) 1:4&#10;C) 1:5&#10;D) 3:1

Accepted Answer

The total volume after mixing is 0.5 mL (serum) + 1.5 mL (diluent) = 2.0 mL. The serum is 0.5 mL of this total, making the dilution 0.5 mL serum / 2.0 mL total = 1:4.

Question 8

Which of the following should be part of a chemical hygiene plan?&#10;A) appropriate work practices&#10;B) engineering controls such as fume hoods&#10;C) employee training&#10;D) all of the above

Accepted Answer

A chemical hygiene plan should include all of the above mentioned elements, including appropriate work practices, engineering controls such as fume hoods, and employee training. The plan should also include procedures for hazard identification and assessment, use and maintenance of personal protective equipment, and emergency response.

Question 9

Which of the following is part of the federal Occupational Exposure to Bloodborne Pathogens Standard Act ?&#10;A) All employees must practice universal precautions at all times.&#10;B) Only workers who come in contact with patients need to wear gloves.&#10;C) Taking a cup of coffee into the lab is okay as long as it doesn't spill.&#10;D) A blood spill can be mopped up at the end of the day.

Accepted Answer

The federal Occupational Exposure to Bloodborne Pathogens Standard Act requires all employees to practice universal precautions at all times, which includes wearing personal protective equipment (like gloves) to avoid contact with blood or other potentially infectious materials. Bringing food or drink into the lab or leaving a blood spill until the end of the day are not addressed by the standard and are not acceptable practices.

Question 10

Which of the following applies to recapping of needles?&#10;A) It can be done carefully as long as gloves are worn.&#10;B) A sheath can be placed back on the needle with the other hand.&#10;C) Transport needles back to the lab for disposal.&#10;D) Never manually recap a needle.

Accepted Answer

OSHA guidelines prohibit the practice of manually recapping needles due to the risk of accidental needlestick injuries. Needles should be disposed of immediately in appropriate sharps containers after use.

Question 11

When a staphylococcal infection is passed between patients due to health-care workers not washing their hands,this represents an example of:&#10;A) lack of chemical hygiene&#10;B) a sharps hazard&#10;C) the chain of infection&#10;D) a specimen transport problem

Accepted Answer

The answer of When a staphylococcal infection is passed between...

Deck 7: Safety and Specimen Preparation