In a serological serial dilution, what is the titer in tube #10 if tube #1 has 1 mL of the undiluted specimen?

In a serological serial dilution, each subsequent tube typically contains half the concentration of the previous tube. If tube #1 has 1 mL of the undiluted specimen, then each tube thereafter is created by taking a portion of fluid from the previous tube and diluting it further.

Assuming a standard dilution factor of 1:2 (where each dilution doubles the volume with an equal volume of diluent, leading to halving the concentration), we can calculate the titer for tube #10. The titer is defined as the inverse of the dilution factor.

• Tube #1 (undiluted) has a titer of 1 (1:1).

• Tube #2 has a titer of 2 (1:2).

• Tube #3 has a titer of 4 (1:4).

• Tube #4 has a titer of 8 (1:8).

• Tube #5 has a titer of 16 (1:16).

• Tube #6 has a titer of 32 (1:32).

• Tube #7 has a titer of 64 (1:64).

• Tube #8 has a titer of 128 (1:128).

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