| UsageWhen you cannot screen by colony PCR, mostly commonly because the insert is too small to generate a band shift or if the insert is of the same length as the cutout from the parent vectorIdeally should screen with restriction enzyme(s) that would cut both positive and negative colonies, but different number of times (e.g., single-cut for negative and double-cut for positive, or vice versa)
 ProcedurePrepare plasmids using Maniatis method; phenol-chloroform extraction is optional if you do not plan to use the plasmid for anything other than screeningSet up 5-ul digestion reaction using the appropriate restriction enzymesShould always include a negative control (most commonly the parent vector)Should include a positive control if possibleAnalyze on agarose gel; should include uncut plasmid for comparison
 |