Team:Heidelberg/n4tr1um

Revision as of 13:25, 17 June 2009 (view source)

Larsplus (Talk | contribs)

(→Site-directed mutagenesis)

← Older edit

Latest revision as of 12:26, 24 June 2009 (view source)

Larsplus (Talk | contribs)

(Removing all content from page)

(12 intermediate revisions not shown)

Line 1:

-

~~== Transformation of Bacteria ==~~

-

For enrichment of vectors, E .coli DH5α were used. For the transformation 100 µl of the competent cells were thawed on ice and 50 – 400 ng DNA solution added (depending on the concentration of the DNA solution). After a 30-60 minute incubation on ice, cells were made permeable for the DNA by heat shocking for 45 seconds at 42 °C and a further 3 minute incubation on ice. The samples were than rescued by adding 500µl preheated antibiotic free LB-medium and incubated for one hour at 37 °C while shaking for induction of the antibiotic resistance. The selection for plasmid containing and therefore antibiotic resistant bacteria was conducted by plating them on antibiotic containing LB-agar plates.

-

~~== Isolation of plasmid DNA by alkaline lysis (mini and maxiprep) ==~~

-

For analysis of ligations and transformations QIAprep Spin Kits (Qiagen, Hilden) were used following the manufacturer instructions. For miniprep a single colony was picked from a LB-agar plate or glycerol stock was used to inoculate 5 ml LB-medium with appropriate antibiotic for selection (100 µg/µl ampicillin, 50 µg/µl kanamycin, 35 µg/µl chloramphenicol). Bacteria were grown over night at 37 °C while shaking (200 rpm). By using 4 ml over night culture with this kit the yield was around 6-10 µg. For maxipreps the Qiagen CompactPrep Plasmid Maxi Kit was used following the instructions given by the instruction manual. In this case 250 ml LB-medium were inoculated and used for preparation of plasmid DNA. The routinely yield was 300-400 µg plasmid DNA. Purity and amount of DNA was analysed using a NanoDrop.

-

~~== Site-directed mutagenesis ==~~

-

For removal of unwanted Restriction Sites, a PCR-based site direct mutagenesis protocol was adapted from [http://www.stratagene.com/manuals/200518.pdf Stratgene]. Oligos were designed to have a high (>78°C) Tm ny applying the formula

-

~~<math> T_{m} = 81{,}5 + 0{,}41 * (%GC) - \frac{675}N - %mismatch </math>~~

@@ Line 1: / Line 1: @@
-== Transformation of Bacteria ==
-For enrichment of vectors, E .coli DH5α were used. For the transformation 100 µl of the competent cells were thawed on ice and 50 – 400 ng DNA solution added (depending on the concentration of the DNA solution). After a 30-60 minute incubation on ice, cells were made permeable for the DNA by heat shocking for 45 seconds at 42 °C and a further 3 minute incubation on ice. The samples were than rescued by adding 500µl preheated antibiotic free LB-medium and incubated for one hour at 37 °C while shaking for induction of the antibiotic resistance. The selection for plasmid containing and therefore antibiotic resistant bacteria was conducted by plating them on antibiotic containing LB-agar plates.
-== Isolation of plasmid DNA by alkaline lysis (mini and maxiprep) ==
-For analysis of ligations and transformations QIAprep Spin Kits (Qiagen, Hilden) were used following the manufacturer instructions. For miniprep a single colony was picked from a LB-agar plate or glycerol stock was used to inoculate 5 ml LB-medium with appropriate antibiotic for selection (100 µg/µl ampicillin, 50 µg/µl kanamycin, 35 µg/µl chloramphenicol). Bacteria were grown over night at 37 °C while shaking (200 rpm). By using 4 ml over night culture with this kit the yield was around 6-10 µg. For maxipreps the Qiagen CompactPrep Plasmid Maxi Kit was used following the instructions given by the instruction manual. In this case 250 ml LB-medium were inoculated and used for preparation of plasmid DNA. The routinely yield was 300-400 µg plasmid DNA. Purity and amount of DNA was analysed using a NanoDrop.
-== Site-directed mutagenesis ==
-For removal of unwanted Restriction Sites, a PCR-based site direct mutagenesis protocol was adapted from [http://www.stratagene.com/manuals/200518.pdf Stratgene]. Oligos were designed to have a high (>78°C) Tm ny applying the formula
-<math> T_{m} = 81{,}5 + 0{,}41 * (%GC) - \frac{675}N - %mismatch </math>

From 2009.igem.org

Latest revision as of 12:26, 24 June 2009