Table 2. Regression statistics of extracted cell cake water versus wash water.

δ18O of growth medium water, ‰	Slope of extracted cell water versus wash water	R2 of regression	y intercept value†	Calculated δ18O of intracellular water, ‰*†
-15.2	0.81	0.99	-1.2	-6.32
-4.9	0.85	0.99	-0.77	-5.13
5.5	0.93	0.99	-0.04	-0.55
16.1	0.86	0.99	+0.32	2.26
	Average = 0.86‡
	Standard error = 0.025

^*The δ¹⁸O value of intracellular water = (y intercept)/(1 - slope). Intracellular water is itself a combination of growth medium water and intracellular water as described by Eq. 3.

^†Average and standard error are not presented, because the y intercept values and the δ¹⁸O values of the intracellular water are expected to be different as a result of the different δ¹⁸O values of the growth medium waters.

^‡These slopes are not statistically different (F = 1.59; F_0.05 = 4.35) (13).