Calculate TCID 50/mL |

TCID
The calculation [Reed, LJ, H Muench. 1938. A simple method of estimating fifty percent endpoints. Am. J. Hygiene 27: 493–497.] assumes a typical assay set up of 5 replicates at each concentration of the infectious agent and the inoculum added to each row of replicates is 10-fold more dilute than that used in the preceding row. The inoculum used in the first row is 1/10 the concentration of the stock to which the TCID
The calculation requires checking only 1 or 2 boxes: ---(1) Check the box corresponding to the number of infected cultures (3 to 5) in the last row from the top with 3 or more (50% or more) infected cultures. ---(2) Check the number of infected cultures (none, 1, or 2) in the row at the next dilution (should be <50% or it would be the row selected in (1)). |

## |---Replicates---| |

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