Part:BBa_K228867
pSB1A2-lacZ screening plasmid
This part is an improved version of pSB1A2, which lacks the NotI in between SpeI and PstI site. A constitutive lacZ alpha generator is placed in the original NotI site. Usually, rbs parts and promoter parts which is relatively small and has a low production after gel purification can be placed in this backbone. This improved plasmid can support blue white screening. Because the original parts on this plasmid is small parts, it is digested to be a vector. By cutting the plasmid with SpeI and PstI, the lacZ generator is removed. Although false positive can be created by religation of singal digestion product, it can be distinguished from the correct colonies by its color. Correct colonies are white while false positive ones are blue.
Fig1. shows one application of the plasmid. The inserted part is a rbs. Most frequently, we put a coding sequence downstream of the rbs, this will eliminate the lacZ sequence, so that the colony become white in the presence of X-gal.
Sequence and Features
- 10INCOMPATIBLE WITH RFC[10]Plasmid lacks a suffix.
Illegal SpeI site found at 2
Illegal PstI site found at 303 - 12INCOMPATIBLE WITH RFC[12]Plasmid lacks a prefix.
Plasmid lacks a suffix.
Illegal EcoRI site found at 2345
Illegal NheI site found at 14
Illegal NheI site found at 37
Illegal SpeI site found at 2
Illegal PstI site found at 303
Illegal NotI site found at 2351 - 21INCOMPATIBLE WITH RFC[21]Plasmid lacks a prefix.
Plasmid lacks a suffix.
Illegal EcoRI site found at 2345 - 23INCOMPATIBLE WITH RFC[23]Illegal prefix found at 2345
Plasmid lacks a suffix.
Illegal SpeI site found at 2
Illegal PstI site found at 303 - 25INCOMPATIBLE WITH RFC[25]Illegal prefix found at 2345
Plasmid lacks a suffix.
Illegal XbaI site found at 2360
Illegal SpeI site found at 2
Illegal PstI site found at 303 - 1000INCOMPATIBLE WITH RFC[1000]Plasmid lacks a prefix.
Plasmid lacks a suffix.
Illegal BsaI.rc site found at 1384
| n/a | pSB1A2-lacZ screening plasmid |