Question

1. 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? A. 32 B. 16 C. 64 D. Cannot be determined 2. If you want to make 2 mL of a 1:20 dilution, how much serum would be needed? 3. When 1.0 mL of serum is added to 3.0 mL of diluent, what dilution does this represent? A. 1:2 B. 1:4 C. 1:20 D. 3: E 1:3 4. If 0.9 mL of saline is added to 0.1 mL of serum, what does the 0.9 mL represent? A. The final dilution B. The diluent C. The solute D. The total solution S. Which series of dilutions would be best in order to make a 1:300 dilution? A. 1:10, 1:3, 1:10 B. 1:5, 1:6, 1:100 C. 1:3, 1:100, 1:10 D. 1:30, 1:10, 1:100 6. If there will be an unavoidable 4-hour delay before a serum sample can be tested, the sample should be: A. kept at room temperature B. refrigerated between 2°C and 8°C. C. frozen at -20°C. D. discarded and a new sample collected when it can be tested immediately

Answer 1

. 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? A)32 B, 16 In immunology, the antibody titer value is calculated by making the serial dilution of the serum sample and then testing each dilution for the detectable levels of the antibody. It is the highest dilution at which the agglutination High titer value indicates higher antibody concentration, thus active infection C. 64 D. Cannot be determined occurs 2. If you want to make 2 mL of a 1:20 dilution, how much serum would be needed? The 1:20 dilution ratio indicates 0.05 mL of serum diluted to 1 mL. So, preparing 2 mL of 1:20 diluted solution requires 0.1 mL of serum.