Cell concentration as a factor in precursor incorporation by tobacco leaf protoplasts or separated cells.

Freshly isolated protoplasts or separated cells prepared from leaves of Nicotiana tabacum L. cvs. Xanthincor Turkish Samsun exhibit substantially greater incorporation of [(3)H] leucine and [(3)H] uridine into protoplast protein and RNA, respectively, when dilute rather than concentrated suspensions are incubated. This phenomenon is considered to result from a dilution of the labeled precursors in the incubation medium by nonlabeled precursors of cellular origin.