To obtain a properly collected and labeled sample, it is preferable to use a tamper-evident, presealed oral swab collection kit. Some laboratories may prefer to have the swabs air-dry for 15 minutes to an hour prior to placing the oral swab in the swab envelope. Although the process of air-drying the swabs may lead to a more pristine sample, the process of air-drying is risky and may inadvertently lead to a sample mixup if more than one person’s sample is collected at a time. The laboratory may also want to incorporate some type of notification system in which the collection location calls or faxes the DNA laboratory when the sample has been collected, alerting the DNA laboratory that the sample is on the way. A tamper-evident, presealed oral swab collection kit may contain:
Collection instructions (See sample Oral Swab Collection Instructions below)
Collection form for family reference sample (See Sample Family and/or Donor Reference Collection Form, appendix C)
Form describing the family relationship (See Sample Family Tree form, appendix D)
Pair of gloves (preferably one-size-fits-all Nitrile gloves)
Sterile, cotton-tipped swabs (2–6)
If the collection is performed correctly on a healthy individual, two swabs are sufficient to get adequate amounts of DNA for a short tandem repeat (STR) analysis. If extended testing may be required, it is preferable to collect six swabs.
Fastener (optional)
A small rubber band or twist-tie may be included to bind together all of the swabs from one individual prior to placing them in the swab envelope. Alternatively, a label may be included to secure and label the swabs.
Swab envelope
Once the swabs have been collected, they should be placed in an envelope that can be uniquely identified with the donor’s information.
Tamper-evident, sealable bag, containing desiccant packet
If mass collections are to be performed, inadvertent sample switches may occur if the swabs are allowed to air-dry in the open; therefore, a desiccant can be used to help keep the moist swab from molding. If a Ziploc bag is used, tamper-evident policeevidence seals can be placed on the bag.
Mailing envelope
A preprinted mailing envelope with an appropriate prepaid shipping label will help ensure that the swabs are delivered to the correct location. Make sure the shipping carrier services the area where the sample will be collected. Different air bills and customs documents may be needed if samples will be shipped from outside the United States.
To avoid sample mixups, identification, collection, and sample sealing should be performed for one individual at a time. Also, it would be advisable to:
Go to Next Section: Appendix F: Issues to Consider When Outsourcing Reference Samples
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