TABLE 2.
Frequencies of the in vitro integration assaya
| Reaction mixture | Presence (+) or absence (−) of indicated substance
|
Frequencyb | ||||
|---|---|---|---|---|---|---|
| attB | attDOT | Int | Bacteroides crude extractc | IHFc | ||
| Experiments | ||||||
| 1 | + | + | + | − | − | 10−7-10−6 |
| 2 | + | + | + | + | − | 10−5-10−4 |
| 3 | + | + | + | − | + | 10−3-10−2 |
| Controls | ||||||
| 4 | + | + | − | − | + | <10−7 |
| 5 | − | + | + | − | + | <10−7 |
| 6 | + | − | + | − | + | <10−7 |
a
The in vitro integration assays were performed as described in Materials and Methods. The integration frequency is expressed as the ratio of Apr Cmr colonies to Apr colonies from the electroporation method.
b
The frequency of integration decreases by about 10-fold after phenol extraction, as shown by the decrease from 10−3 to 10−4 after phenol extraction for reaction with IHF.
c
Either Bacteroides crude extract or IHF was added to the control reaction mixtures; both additives gave the same results.