Exam 8: Serology Laboratory Math

A microgram is

Children who flew in an trans-Atlantic airplane have been exposed to the new virulent strain of influenza. A laboratory has developed a 6-minute antigen assay from nasal swabs to diagnose the disease. The lab ran this test on 1000 samples. In a longer test that is considered the gold standard assay, 200 of these samples were found to be true positives and 800 true negatives. When tested by the new antigen assay, 150 of the true positives tested positive, and 790 of the true negative samples tested negative. What is the specificity of this antigen assay?

A nanometer is

Children who flew in an trans-Atlantic airplane have been exposed to the new virulent strain of influenza. A laboratory has developed a 6-minute antigen assay from nasal swabs to diagnose the disease. The lab ran this test on 1000 samples. In a longer test that is considered the gold standard assay, 200 of these samples were found to be true positives and 800 true negatives. When tested by the new antigen assay, 150 of the true positives tested positive, and 790 of the true negative samples tested negative. What is the sensitivity of this assay?

If you have 5 ml of a 1:20 dilution and add 5 more ml, what dilution do you now have?

Group B Strep that an infant is exposed to in the vaginal canal can cause neonatal fatalities in 48 hours, and the current test for diagnosis can take 24-48 hours. A laboratory has developed a 6-hour antigen assay to diagnose the disease. The lab ran this test on 2000 samples. Using the gold standard assay of culture, 500 of these samples were found to be true positives and 1500 true negatives. When tested by the new antigen assay, 450 of the true positives tested positive, and 1485 of the negative samples tested negative. What is the efficiency of the assay?

If I have 0.2 ml of a 1:10 dilution and need a 1:40 dilution, how much buffer should I add?

A hospital has a high incidence of Group B neonatal sepsis, that is, 4 cases per 1000 live births. Applying the specificity above, what is the positive predictive value?

The definition of titer is the

Group B Strep that an infant is exposed to in the vaginal canal can cause neonatal fatalities in 48 hours, and the current test for diagnosis can take 24-48 hours. A laboratory has developed a 6-hour antigen assay to diagnose the disease. The lab ran this test on 2000 samples. Using the gold standard assay of culture, 500 of these samples were found to be true positives and 1500 true negatives. When tested by the new antigen assay, 450 of the true positives tested positive, and 1485 of the negative samples tested negative. What is the sensitivity of this assay?

What is the dilution of the fourth tube in a 1:10 serial dilution if the first tube is a 1:3 dilution?

If you make a 1:10 dilution and follow it with a 1:5 dilution, what dilution do you now have?

Children who flew in an trans-Atlantic airplane have been exposed to the new virulent strain of influenza. A laboratory has developed a 6-minute antigen assay from nasal swabs to diagnose the disease. The lab ran this test on 1000 samples. In a longer test that is considered the gold standard assay, 200 of these samples were found to be true positives and 800 true negatives. When tested by the new antigen assay, 150 of the true positives tested positive, and 790 of the true negative samples tested negative. What is the efficiency of the assay?

What dilution does a 1:2 dilution of a 1:0 dilution give?

What is the dilution of the fifth tube in a 2-fold serial dilution when the first tube's dilution is 1:10?

A milligram is

One hundred children with strep throat are tested by a new technique; 98 of them test positive and 2 of them test negative. One hundred children who do not have strep are also tested, and 5 of them test positive.

Group B Strep that an infant is exposed to in the vaginal canal can cause neonatal fatalities in 48 hours, and the current test for diagnosis can take 24-48 hours. A laboratory has developed a 6-hour antigen assay to diagnose the disease. The lab ran this test on 2000 samples. Using the gold standard assay of culture, 500 of these samples were found to be true positives and 1500 true negatives. When tested by the new antigen assay, 450 of the true positives tested positive, and 1485 of the negative samples tested negative. What is the specificity of this antigen assay?

If I make a 1:10 dilution, take 0.2 ml of it, and add 0.8 ml of buffer to it, what is the new dilution?

A hospital has a high incidence of this new strain of influenza, and that is 4 cases per 10000 live births. Applying the specificity found in question 17 what is the positive predictive value.