Which control shows the correct result for a valid ASO test?

Which control shows the correct result for a valid ASO test?

• A. SLO control, no hemolysis
• B. Red cell control, no hemolysis
• C. Positive control, hemolysis in all tubes
• D. Hemolysis in both SLO and red cell control

Answer: (B)

In an Antistreptolysin O (ASO) test, the goal is to detect the presence of antibodies against streptolysin O, which is a toxin produced by Group A Streptococcus. The test evaluates how serum reacts in response to this toxin. A valid ASO test requires both positive and negative controls to ensure that the test is functioning properly. The correct control for a valid ASO test shows no hemolysis with red cell control because it indicates that the red blood cells are not affected by the ASO antigens present in the serum being tested. If the red cell control demonstrates no hemolysis, it confirms that the reagents and the testing conditions are appropriate, and any hemolysis seen in the test sampler can be attributed to specific interactions with the streptolysin O. This is critical because hemolysis in controls can indicate either an issue with reagent interaction or contamination. For instance, hemolysis in a positive control could suggest the presence of ASO antibodies, but in the context of a control, it does not serve the purpose of validating the test, as hemolysis should ideally occur only in the presence of specific reactivity to the streptolysin O, not in a control meant

In an Antistreptolysin O (ASO) test, the goal is to detect the presence of antibodies against streptolysin O, which is a toxin produced by Group A Streptococcus. The test evaluates how serum reacts in response to this toxin. A valid ASO test requires both positive and negative controls to ensure that the test is functioning properly.

The correct control for a valid ASO test shows no hemolysis with red cell control because it indicates that the red blood cells are not affected by the ASO antigens present in the serum being tested. If the red cell control demonstrates no hemolysis, it confirms that the reagents and the testing conditions are appropriate, and any hemolysis seen in the test sampler can be attributed to specific interactions with the streptolysin O. This is critical because hemolysis in controls can indicate either an issue with reagent interaction or contamination.

For instance, hemolysis in a positive control could suggest the presence of ASO antibodies, but in the context of a control, it does not serve the purpose of validating the test, as hemolysis should ideally occur only in the presence of specific reactivity to the streptolysin O, not in a control meant