Plant tissue culture formulas

$V_1$ is the volume of stock at concentration $C_1$ needed to make volume $V_2$ of medium at concentration $C_2$. Put both concentrations in one unit and both volumes in one unit before substituting (1 mg/mL = 1000 mg/L).

Biomass concentration $X$ at time $t$ during the exponential phase; $X_0$ is the biomass at the start of that phase and $\mu$ the specific growth rate.

Calculated from two points within the exponential phase; the unit is per time (for example per day).

Time for biomass to double in the exponential phase; $t_d$ is in the same time unit as $1/\mu$.

Number of doublings $n$ needed to grow from $X_0$ to $X$ in the exponential phase; they take time $t=n{t}_d$.

$X_i$ is the initial and $X_f$ the final fresh weight, dry weight or cell concentration of a culture cycle; it is a ratio with no unit. Some define growth index as the fold increase $X_f/X_i$ instead, so check which definition a question uses.

Biomass formed per unit of substrate (for example sucrose) consumed over the same interval; in g biomass per g substrate when $X$ and $S$ are both in g/L.

Volume of the settled or centrifuged cell pellet as a percentage of the total culture volume sampled.