Salmonella Antisera Quiz

What is the vial volume for the O, H, and monoclonal Vi antisera that allows for 150 tests?

• 1 ml

• 2 ml

• 3 ml

• 4 ml

Answer explanation

To perform 150 tests, each requiring 20 µl of antisera, a total of 3000 µl (or 3 ml) is needed. Therefore, the vial volume for the O, H, and monoclonal Vi antisera that allows for 150 tests is 3 ml.

Which antisera type is used for inversion of H phases?

• O, H, and monoclonal Vi

• Phase Inversion

• Poly A-E+Vi

• Poly H

Answer explanation

The correct choice is 'Phase Inversion' as it specifically refers to the process used for the inversion of H phases in serological testing, distinguishing it from other antisera types listed.

What is the principle behind the use of Salmonella antisera?

• DNA sequencing

• Antigen-antibody complex formation

• Protein synthesis

• Cell division

Answer explanation

The principle behind the use of Salmonella antisera is based on antigen-antibody complex formation. Antisera contain antibodies that specifically bind to Salmonella antigens, allowing for detection and identification of the bacteria.

What should be confirmed before using SSI Diagnostica Salmonella antisera?

• The strain is a Salmonella

• The strain is a virus

• The strain is a fungus

• The strain is a bacteriophage

Answer explanation

Before using SSI Diagnostica Salmonella antisera, it is crucial to confirm that the strain is a Salmonella. The antisera is specifically designed to identify and react with Salmonella bacteria, not viruses, fungi, or bacteriophages.

What can cause false positive reactions when using antisera?

• Rough cultures/strains

• Smooth cultures/strains

• Diluted cultures/strains

• Filtered cultures/strains

Answer explanation

Rough cultures/strains can lead to false positive reactions when using antisera due to their irregular surface structures, which may cross-react with the antibodies, unlike smooth cultures that are more specific.

How soon should the result be read for slide agglutination using antisera?

• Within 10 seconds

• Within 30 seconds

• Within 1 minute

• Within 5 minutes

Answer explanation

The result of slide agglutination using antisera should be read within 10 seconds to ensure accurate interpretation of agglutination reactions, as delays can lead to false results.

What should be done if turbidity due to lipoprotein precipitation occurs?

• Centrifugation and sterile filtration

• Heating and cooling

• Adding more antisera

• Shaking vigorously

Answer explanation

Centrifugation and sterile filtration effectively remove turbidity caused by lipoprotein precipitation, ensuring a clear sample. Other options like heating or adding more antisera do not address the turbidity issue directly.

What should be done with antisera that have accidentally been frozen?

• They should not be used

• They should be thawed and used

• They should be diluted

• They should be heated

Answer explanation

Antisera that have been accidentally frozen can lose their effectiveness and may not provide reliable results. Therefore, they should not be used.

What is the recommended storage temperature for Salmonella antisera?

• 0-2 °C

• 2-8 °C

• 10-15 °C

• 20-25 °C

Answer explanation

The recommended storage temperature for Salmonella antisera is 2-8 °C. This range helps maintain the stability and efficacy of the antisera, ensuring it remains effective for diagnostic purposes.

Which of the following is used as a preservative in Salmonella antisera?

• Sodium chloride

• Sodium azide

• Potassium iodide

• Calcium carbonate

Answer explanation

Sodium azide is commonly used as a preservative in Salmonella antisera due to its ability to inhibit bacterial growth, ensuring the stability and longevity of the antisera.