What is the titer in tube No. 8 if tube No. 1 is undiluted and dilutions are doubled?

What is the titer in tube No. 8 if tube No. 1 is undiluted and dilutions are doubled?

• A. 64
• B. 128
• C. 256
• D. 512

Answer: (B)

To determine the titer in tube No. 8 with the given scenario, it's important to understand how serial dilutions are performed. In this case, if tube No. 1 is undiluted and subsequent dilutions are doubled, this means that each subsequent tube is half the concentration of the previous one. Starting with tube No. 1 as undiluted (let’s denote this concentration as 1), the following tubes would have concentrations as follows: - Tube No. 1: 1 (undiluted) - Tube No. 2: 1/2 (first dilution) - Tube No. 3: 1/4 (second dilution) - Tube No. 4: 1/8 (third dilution) - Tube No. 5: 1/16 (fourth dilution) - Tube No. 6: 1/32 (fifth dilution) - Tube No. 7: 1/64 (sixth dilution) - Tube No. 8: 1/128 (seventh dilution) The titers are denominated as 1 divided by the dilution factor. Therefore, the titer for tube No. 8, which corresponds to a dilution of

To determine the titer in tube No. 8 with the given scenario, it's important to understand how serial dilutions are performed. In this case, if tube No. 1 is undiluted and subsequent dilutions are doubled, this means that each subsequent tube is half the concentration of the previous one.

Starting with tube No. 1 as undiluted (let’s denote this concentration as 1), the following tubes would have concentrations as follows:

• Tube No. 1: 1 (undiluted)

• Tube No. 2: 1/2 (first dilution)

• Tube No. 3: 1/4 (second dilution)

• Tube No. 4: 1/8 (third dilution)

• Tube No. 5: 1/16 (fourth dilution)

• Tube No. 6: 1/32 (fifth dilution)

• Tube No. 7: 1/64 (sixth dilution)

• Tube No. 8: 1/128 (seventh dilution)

The titers are denominated as 1 divided by the dilution factor. Therefore, the titer for tube No. 8, which corresponds to a dilution of