Use of (1 or 3-3H, U-14C)glucose to estimate the synthesis of glycerolipids via acyl dihydroxyacetone phosphate.

Turnover rates of tRNAs in Friend virus-infected mouse leukemia cells are reported. Cells were labeled for one generation with [¹⁴C]- or [³H]uridine. ³H-labeled cells were transferred to nonradioactive medium and allowed to grow exponentially for 72 hours. Low molecular weight cytoplasmic RNAs isolated from ¹⁴C- and ³H-labeled cells were cochromatographed on reverse-phase columns. The results indicate considerable heterogeneity of turnover rates of 4S RNAs, with the most labile species turning over at least 1.75 times as fast as the most stable species.