TABLE 1.

The stability of sequences selected by in vivo selection^a

Insert	Sequence design of insert	Transformation efficiency (CFU/μg of DNA)
A	In vivo selection	1.2 ± 0.5 × 105
B	In vivo selection	0.9 ± 0.3 × 105
C	In vivo selection	3.1 ± 0.9 × 105
D	Codon usage	<102
None		5.3 ± 1.3 × 106

^aCompetent cells of E. coli HB101 (Nippon Gene, Toyama, Japan) have transformation ability of 10⁸ CFU/μg of DNA (pBR322). Transformation was performed four times for each vector insert according to the protocol recommended by the manufacturer. Transformation efficiency values are the averages of the results of four transformation experiments. The DNA sequences of the inserts are as follows: A, GGAGCCCCGGGTGCTCCGGGTGCACCGGGTCCGGTTGGTCCGGCTGGTAAATCTGGTGACCGTGGTGAAACAGGTCCTGCAGGTCCGCCG; B, GGAGCCCCAGGTGCTCCAGGAGCACCGGGTCCAGTCGGGCCGGCAGGAAAATCAGGAGATCGCGGAGAAACAGGTCCTGCAGGACCACCA; C, GGAGCCCCAGGTGCTCCCGGAGCACCAGGACCAGTCGGGCCGGCAGGTAAATCTGGGGACCGCGGCGAGACGGGTCCTGCTGGACCACCA; and D, GGAGCCCCGGGCGCGCCCGGTGCGCCGGGACCAGTCGGGCCGGCAGGAAAATCAGGGGACCGTGGTGAAACGGGTCCTGCAGGACCACCA.