Table 2. Approximate concentrations of ribosomal components in translating iSAT reactions.

	Approximately concentration of each component in iSAT reaction (nM)
	No additives	2% PEG 2000	2mM DTBA	2%PEG 6000/2mM DTBA
30S + 50S	192	212	153	139
70S	65	62	102	98
Polysomes	7	7	13	8
Total	264	281	268	253

Ribosome profiles of translating iSAT reactions (Figure 5E–H) were analyzed from 5 to 17 ml elution volumes, with the separation of 50S and 70S peaks and 70S and polysome peaks determined by drop-down approximation from the lowest value between the peaks (∼11 and 15 ml, respectively). Areas under peaks were determined and converted to concentrations using the areas under peaks of known quantities of purified 70S ribosomes on sucrose gradients.