How do I determine the isotonic state of a grape cell, the point at which no water would enter or gain a cell?

I did an experiment including grapes in which I got these results (can someone post the link without the spaces?)

h t t p : / / i 2 5 . t i n y pi c. c o m / 2 m o v v x i. j p g

and I did this best fit line graph (click on next link) But I don't know how to find the isotonic state of the grape cell. h t t p : / / i 2 5 . t i n y p i c . c o m / s m p x 1 j . j p g

1 answer

http://i25.tinypic.com/2movvxi.jpg

http://i25.tinypic.com/smpx1j.jpg