|
 |
 |
Technical Support:
FAQ
FAQ
Technical support for any of our products is available from 9:00am to 5:00pm EST. Please call 1.613.723.5757 ext. 235 or email us at support@dnagenotek.com.
FREQUENTLY ASKED QUESTIONS
Collection
| Q. |
What is the DNA yield? |
| A. |
From a study of 208 samples, the median amount of DNA was 110 ug per 2 mL of saliva, and the average was 100 ug. The 25% percentile was 62 ug and the 75% percentile was 158 ug. The range was 10 to 375 ug. Click here for the complete whitepaper. |
| Q. |
What is the best way to quantify my DNA yield? |
| A. |
We recommend quantifying your DNA with a fluorescent dye such as SYBR Green or PicoGreen (Molecular Probes) because these dyes bind to double-stranded DNA. Quantification by absorbance will tend to over-estimate the amount of DNA because of absorbance by RNA co-purified with the DNA. For more details, please consult our quantification protocol. |
| Q. |
The median yield of my Oragene•DNA samples is lower than 110 ug. Why is this? |
| A. |
There is a degree of variability in the amount of DNA in saliva. Even in the same donor, the amount of DNA in saliva can vary from day to day. |
| Q. |
What can I do to increase the yield of DNA? |
| A. |
DNA yield is proportional to the volume of saliva that is collected. To get more DNA, ask donors to spit more saliva. Although the standard Oragene•DNA instructions ask donors to spit 2 mL of saliva, the Oragene•DNA chemistry can preserve up to 4 mL of saliva. Click here for the complete whitepaper. |
| Q. |
Does the Oragene•DNA kit still work if someone spits less than 2 mL of saliva? |
| A. |
Yes, the Oragene•DNA chemistry can preserve a wide range of saliva volumes - from microliters up to 4 mL of saliva. Click here for the complete whitepaper. |
| Q. |
What is the source of the DNA in saliva? |
| A. |
The source of DNA is buccal epithelial cells and white blood cells. |
| Q. |
How much bacterial DNA is in my Oragene•DNA samples?? |
| A. |
Using a real-time PCR assay with bacterial 16S rRNA primers, the median amount of bacterial DNA was 6.8%, with a range from 2 to 29%. In comparison, DNA collected with mouthwash contains about 50% bacterial DNA and buccal swabs may be almost 90% bacterial. The small amount of bacterial DNA content in Oragene•DNA does not affect downstream applications. Click here for the complete whitepaper. |
| Q. |
Do you have any recommendations on how to conduct a mailing study with the Oragene•DNA kits? |
| A. |
Yes, please consult our
Mailing Recommendations. |
Storage
| Q. |
What temperature should I store my saliva samples in Oragene•DNA? |
| A. |
The Oragene•DNA DNA-preserving solution stabilizes the DNA in saliva across a range of temperatures. Saliva samples may be stored at room temperature, 4°C in the refrigerator, or frozen at temperatures such as -20°C or -80°C, depending on which is most convenient for you. Please consult our "DNA Stability with Oragene•DNA" application note for more details. |
| Q. |
Can saliva samples in Oragene•DNA frozen and then thawed? |
| A. |
Yes, saliva samples may undergo at least five freeze-thaw cycles with no evidence of DNA degradation. Please consult our "Long-term Storage Recommendations" application note for more details. |
Purification
| Q. |
The A260/280 ratio of my purified DNA is low. What can I do to improve this? |
| A. |
DNA from saliva purified with the Oragene•DNA ethanol precipitation protocol should have A260/280 ratios ranging from 1.6 to 1.9. If your ratio is low, try the following trouble-shooting tips:
(1) check that the Oragene•DNA samples have been incubated for at least 1 hour at 50°C before purification,
(2) when purifying the Oragene•DNA sample, be sure not to disturb the protein pellet after the first centrifugation step,
(3) check that your spectrophotometer is subtracting the A320 value from the A260 and A280 values (A320 represents the background turbidity of the sample), and
(4) check that the individual A260 and A280 values are in the range from 0.1 to 1.0 ( i.e. within the linear range of the spectrophotometer).If the A260/280 ratios are still low after following the trouble-shooting tips, please contact Technical Support by email or call
1-613-723-5757. |
| Q. |
Can saliva samples stored in Oragene•DNA be purified using methods other than the ethanol precipitation protocol supplied with the kit? |
| A. |
Yes, homebrew methods such as phenol/chloroform extraction or commercial kits such as QIAamp (Qiagen) and PUREGENE (Gentra) may be used to purify DNA from Oragene•DNA samples. Please see our purification application notes for more information. |
| Q. |
Can saliva samples stored in Oragene•DNA be purified using automated DNA extraction robots? |
| A. |
Yes, DNA from Oragene•DNA samples have been purified using robots such as the BioRobot EZ1 (Qiagen), AutoPure (Gentra), Magtration 12GC (PSS Bio), MagNA Pure LC (Roche), among others. Please see our purification application notes for more information. |
| Q. |
When I run an agarose gel on my purified DNA, there is a large smear at the bottom of the gel. Is this degraded DNA? |
| A. |
No, the smear is low molecular weight RNA. |
Downstream Applications
| Q. |
Which downstream applications are compatible with DNA from Oragene•DNA? |
| A. |
DNA from Oragene•DNA is fully functional with PCR, real-time PCR, multiplex PCR, SNP genotyping, microarrays, sequencing, RFLP, etc. Please see our application notes for more information. |
| Q. |
Does the bacterial DNA in Oragene•DNA samples interfere with downstream applications? |
| A. |
DNA from Oragene•DNA performs the
same as DNA from blood for downstream applications
because the amount of bacterial DNA in Oragene•DNA samples
is low, and PCR-based technologies have good specificity.
For your interest, our application note entitled
"SNP
genotyping of Oragene•DNA™ with SNP stream®"
shows that the SNP genotyping calls are identical
with DNA from blood versus DNA from Oragene•DNA. |
| Q. |
Do you have any recommendations for using DNA from Oragene•DNA with Affymetrix chips? |
| A. |
Yes, for Affymetrix applications, we recommend purifying the Oragene•DNA samples with either the QIAamp DNA Mini Kit (Qiagen) or the PUREGENE kit (Gentra). Also, some users have found it best to incubate the Oragene•DNA saliva samples for 1 hour at 50°C, and not overnight. |
To order call 1.613.723.5757 ext. 1 or email us at sales@dnagenotek.com
|
|
 |
 |
|
|
