Table 1.
Lambda to E. coli ratio
| Experiment | # E. coli/FOV | # FOV | # Lambda/FOV | # FOV | # Lambda/# E. coli |
|---|---|---|---|---|---|
| 1 | 0.60 | 10 | 0.61 | 107 | 1.02 |
| 2 | 0.31 | 50 | 0.30 | 102 | 0.97 |
| 3 | 0.28 | 38 | 0.29 | 96 | 1.04 |
| 4 | 0.78 | 10 | 0.72 | 46 | 0.92 |
| 5 | 0.58 | 36 | 0.65 | 116 | 1.12 |
| 6 | 0.61 | 40 | 0.56 | 100 | 0.92 |
| 7 | 0.31 | 41 | 0.31 | 110 | 1.00 |
| 8 | 0.38 | 100 | 0.47 | 107 | 1.24 |
Results of measurements of combed genomic DNA of RW597(λa)1 E. coli (20). The total length in μm was divided by 2,320 and by the number of FOVs to get an average number of E. coli genomes per FOV (# E. coli /FOV). The same measurement was performed after hybridization of a lambda probe on a larger number of randomly chosen FOV to obtain an average number of lambda genomes per FOV (# Lambda/FOV). Although this average number varies from slide to slide, the final ratio of lambda genomes to E. coli genomes remains close to the expected 1:1 ratio (1.03 ± 0.11).