Final answer:
The final dilution factor after a 1:2 dilution followed by four 1:8 serial dilutions is 1:8192, which is obtained by multiplying the individual dilution factors (1/2 × 1/8 × 1/8 × 1/8 × 1/8).
Step-by-step explanation:
To calculate the final dilution factor after performing a series of dilutions, we need to multiply the individual dilution factors together. Initially, we have a 1:2 dilution, which means the substance is diluted to half of its concentration. After this, performing four 1:8 serial dilutions means each step dilutes the substance to one eighth of the previous concentration.
- First dilution: 1/2
- Second dilution: 1/8
- Third dilution: 1/8
- Fourth dilution: 1/8
- Fifth dilution: 1/8
When we multiply these together, we get the final dilution factor:
(1/2) × (1/8) × (1/8) × (1/8) × (1/8) = 1/2^1 × 1/2^12 = 1/2^13 = 1/8192
The final dilution factor is 1:8192, which is not one of the options provided. The correct answer is therefore not listed among the options A) 1:16, B) 1:32, C) 1:64, D) 1:128.