Common Laboratory Protocols

Bacterial Transformation

Materials: plasmid DNA (up to 100ng, no more than 5μL); Competent bacteria aliquot (stored -80°C); SOC (stored 4°C)

Procedure

Prewarm 2 water baths to 37°C and 42°C
Aliquot 100μL SOC into microcentrifuge tube. Prewarm in 37°C.
Prewarm LB plate + resistance to 37°C.
Add DNA to compontent cells. Incubate on ice 15-20 min.
Heat shock by quickly transferring tubes from ice to 42°C water bath for EXACTLY 45 seconds.
Recuperate for 2 minutes on ice.
Transfer prewarmed SOC to bacteria. Incubate 30 min 37°C.
Transfer all the solution to LB plate. Spread and wait 15 min on benchtop.
Invert and incubate 37°C overnight.

Qiagen protocol generally used

Materials: DNA sample ran through agarose gel; sharp edge, like scalpel or gel cutter; Qiagen Buffers QG, PE, EB; Isopropanol

Procedure

Prewarm waterbath to 50°C
Excise the DNA fragment from the agarose gel with a clean, sharp scalpel.
Weigh the gel slice in a colorless tube. Add 3 volumes of Buffer QG to 1 volume of gel (100 mg ~ 100 µl)
Incubate at 50°C for 10 min (or until the gel slice has completely dissolved). To help dissolve gel, mix by vortexing the tube every 2–3 min during the incubation.
After the gel slice has dissolved completely, check that the color of the mixture is yellow (similar to Buffer QG without dissolved agarose).
Add 1 gel volume of isopropanol to the sample and mix.
Place a QIAquick spin column in a provided 2 ml collection tube.
To bind DNA, apply the sample to the QIAquick column, and centrifuge for 1 min.
Discard flow-through and place QIAquick column back in the same collection tube.
(Optional): Add 0.5 ml of Buffer QG to QIAquick column and centrifuge for 1 min.
To wash, add 0.75 ml of Buffer PE to QIAquick column and centrifuge for 1 min.
Discard the flow-through and centrifuge the QIAquick column for an additional 1 min at ≥10,000 x g (~13,000 rpm).
Place QIAquick column into a clean 1.5 ml microcentrifuge tube.
To elute DNA, add 50 µl of Buffer EB (10 mM Tris·Cl, pH 8.5) or H2O to the center of the QIAquick membrane and centrifuge the column for 1 min at maximum speed.

Qiagen protocol generally used

Materials: 5mL of overnight bacteria culture; Qiagen Buffers P1, P2, N3, PE, EB

Procedure

Resuspend pelleted bacterial cells in 250 µl Buffer P1 and transfer to a microcentrifuge tube.
Add 250 µl Buffer P2 and gently invert the tube 4–6 times to mix
Add 350 µl Buffer N3 and invert the tube immediately but gently 4–6 times.
Centrifuge for 10 min at 13,000 rpm (~17,900 x g) in a table-top microcentrifuge.
Apply the supernatants from step 4 to the QIAprep spin column by decanting or pipetting.
Centrifuge for 30–60 s. Discard the flow-through.
(Optional): Wash the QIAprep spin column by adding 0.5 ml Buffer PB and centrifuging for 30–60 s. Discard the flow-through.
Wash QIAprep spin column by adding 0.75 ml Buffer PE and centrifuging for 30–60 s.
Discard the flow-through, and centrifuge for an additional 1 min to remove residual wash buffer.
Place the QIAprep column in a clean 1.5 ml microcentrifuge tube. To elute DNA, add 50 µl Buffer EB (10 mM Tris·Cl, pH 8.5) or water to the center of each QIAprep spin column, let stand for 1 min, and centrifuge for 1 min.

Materials: 10x Buffer (Compatible to the enzyme); Enzyme; BSA - diluted to 10x; ddH2O; DNA - up to 1μg per reaction.

Procedure Verify all times and temperatures for specific enzyme prior to use. This is general protocol.

Set up reactions based on table below.

Materials

DNA source - commercially made oligo's

Terminal Transferase (NEB - M0315S)

Procedure

Materials: DNA source - commercially made oligo's; Terminal Transferase (NEB - M0315S); CleanAmp dNTP's (TriLink - N9507)

Procedure
repeat for each nucleotide

Controls