Quiz: Sample Handling and Preservation Techniques — 9 perguntas

1. Which practice is essential for maintaining the integrity of photosensitive samples during transport?

A. Recording incidents during transport

B. Transporting primary containers vertically

C. Shielding samples from light throughout transport

D. Labeling containers with dry ice information

Answer: (C)

Explicação

The source explicitly states that photosensitive samples must be shielded from light throughout transport to preserve their integrity, making this the correct practice. Recording incidents and proper labeling are also important but are not specific to photosensitive samples' light sensitivity. Transporting containers vertically is not recommended; horizontal positioning is preferred.

2. What is the effect of incomplete blood coagulation prior to centrifugation?

A. It causes hemolysis of red blood cells, leading to unreliable results

B. It results in fibrin formation that contaminates serum and compromises test accuracy

C. It leads to dilution of blood components, affecting concentration measurements

D. It increases the risk of bacterial contamination during sample handling

Answer: (B)

Explicação

Incomplete coagulation prior to centrifugation results in fibrin formation, which can contaminate the serum sample and interfere with accurate laboratory testing, as explicitly described in the source.

3. Which of the following practices can help prevent hemolysis during blood sample collection and handling?

A. Ensuring the blood sample is exposed to light to stabilize cell membranes

B. Controlling temperature changes to avoid thermal shock

C. Using a smaller needle to minimize mechanical damage

D. Delaying centrifugation to allow cells to settle

Answer: (B)

Explicação

Controlling temperature changes during sample handling can prevent thermal shock, a known cause of hemolysis. The source states that light exposure does not cause hemolysis, so exposing samples to light is not a preventive practice. Delaying centrifugation increases hemolysis risk, not decreases it. Using a smaller needle may reduce pain but does not directly prevent hemolysis caused by temperature or handling issues.

4. What is a characteristic of first morning urine samples according to the source?

A. They are less concentrated than samples collected later in the day

B. They have lower osmolality than random samples

C. They are more concentrated and less affected by diet

D. They are more influenced by recent dietary intake

Answer: (C)

Explicação

First morning urine samples are more concentrated in chemical constituents and formed elements, and they are less influenced by recent dietary intake, providing a more accurate baseline assessment. The source states that these samples tend to have higher osmolality, not lower, and are more, not less, concentrated.

5. What is the recommended abstinence period before semen sample collection to ensure optimal quality?

A. Immediately after ejaculation

B. 24 hours

C. 1 week

D. 2 to 7 days

Answer: (D)

Explicação

The source specifies that the recommended abstinence period before semen collection is between 2 and 7 days, not just 24 hours, to ensure the sample's quality and reliability for fertility assessment.

6. What is the primary function of controlling light conditions during the determination of porphyrins and vitamin D in laboratory tests?

A. To accelerate the reaction speed of chemical assays

B. To prevent microbial contamination of samples

C. To ensure the stability of analytes for accurate measurement

D. To reduce sample volume needed for testing

Answer: (C)

Explicação

Controlling light conditions during the measurement of porphyrins and vitamin D is essential to prevent degradation or alteration of these analytes, ensuring accurate and reliable test results.

7. How does confirming patient identity differ from contamination considerations in sample collection criteria?

A. Patient identity confirmation is optional, but contamination considerations are mandatory.

B. Contamination considerations are more important than patient identity verification.

C. Confirming patient identity is a mandatory step, while contamination considerations depend on handling practices.

D. Both patient identity confirmation and contamination considerations are equally mandatory.

Answer: (C)

Explicação

The source explicitly states that confirming patient identity is a mandatory part of sample collection to prevent errors, whereas contamination considerations are more related to handling practices and are not described as mandatory verification steps. Therefore, confirming patient identity is a more critical, obligatory aspect compared to contamination considerations, which depend on collection and handling.

8. What is the main source of fecal odor according to the provided information?

A. Microbial processes in the gut that modify compounds like bilirubin

B. Iron content in feces from dietary sources or blood breakdown

C. The presence of pigments such as stercobilin and urobilin in feces

D. Chemical reactions unrelated to microbial activity

Answer: (A)

Explicação

The fecal odor mainly comes from microbial processes in the gut that break down and modify compounds like bilirubin. The pigments stercobilin and urobilin contribute to color but are not responsible for the smell. Iron content does not significantly influence fecal odor, and chemical reactions unrelated to microbes are not indicated as primary odor sources.

9. When was the protocol for storing CSF samples at 35±2 ºC or room temperature to preserve pathogen viability established?

A. In the 1980s

B. In the early 20th century

C. During the 1950s

D. In the 2000s

Answer: (A)

Explicação

The establishment of specific storage guidelines, such as maintaining CSF samples at 35±2 ºC or room temperature to preserve pathogen viability, reflects advances in microbiological diagnostic standards. These protocols became more standardized and widely adopted in the late 20th century, particularly in the 1980s, when microbiology and clinical pathology practices were significantly refined.