Presented by: Robert O'Brien Training Specialist – Forensic Biology DNA IQ™ Extraction Presented by: Robert O'Brien Training Specialist – Forensic Biology

Overview The DNA IQ™ extraction uses a paramagnetic resin to isolate DNA. The first step, like most forensic DNA extractions, is solubilization of the dried stain. Many times this step also lyses cells. The second step uses the paramagnetic resin to bind the DNA while leaving the other components from the biological stain in the aqueous solution.

Overview, cont. The DNA IQ™ System uses silica-coated magnetic beads. The quantity of beads used in the procedure defines the binding capacity, which is approximately 100ng of DNA. The DNA IQ™ kit contains the proprietary resin and specialized buffers, including lysis, wash, and elution.

Important Information DNA isolated using the DNA IQ™ protocol is single-stranded. The Elution Buffer releases the DNA from the resin. If the DNA sample has not been heated sufficiently, the efficiency of elution will be lower than expected.

Important Information The resin settles out of solution readily. It is important to mix the resin often when isolating DNA from numerous samples. Vortex the sample vigorously to keep the resin in solution during binding and break up aggregates that may form between each wash step. The presence of aggregates will also lower DNA yield.

Important Information Do not let the resin dry completely after washing. The DNA will bind irreversibly to the resin if this occurs.

Incubation Step One The sample is placed into an extraction tube with lysis buffer. The tube is mixed and centrifuged. The tube is incubated at 70°C for at least 30 minutes.

Clarification Step 2: Transfer any solid material (substrate) into a spin basket. Centrifuge. Discard basket and substrate.

Purification Resin Binding Suspend the DNA IQ Resin stock and add resin to each sample. Note: The resin settles quickly; re-suspend it periodically to ensure that a uniform amount is added to each sample. Mix each sample to suspend the resin, and incubate at room temperature for 5 minutes.

Washing Place tube in the magnetic stand. Once the resin has collected on the side of the tube, carefully remove the liquid. Add prepared Lysis Buffer, remove the tube from the stand and mix briefly. Place tube in the magnetic stand and carefully remove the liquid.

Washing, cont. Add prepared Wash Buffer, remove the tube from the stand and mix briefly. Place tube in the magnetic stand and carefully remove the liquid. Repeat twice. Allow the samples to air dry in the magnetic stand for 5 minutes. Note: Ensure that all traces of liquid have been removed from the tube prior to air drying the resin.

Elution Add Elution Buffer to each tube. Remove tube from the stand, mix briefly and incubate at 65°C for 5 minutes. Remove the tube from the heat, mix briefly and immediately place on the magnetic stand. Recover the liquid and estimate the volume.

DNA Quantitation After elution, the DNA is ready for quantitation