Fta Paper

Another approach to DNA extraction involves the use of FTA™ paper. In the late 1980s, FTA™ paper was developed by Lee Burgoyne at Flinders University in Australia as a method for storage of DNA (Burgoyne et al. 1994). FTA™ paper is an absorbent cellulose-based paper that contains four chemical substances to protect DNA molecules from nuclease degradation and preserve the paper from bacterial growth (Burgoyne 1996). As a result, DNA on FTA™ paper is stable at room temperature over a period of several years. However, a recent study evaluating FTA™ and three other commercial papers as DNA storage media found little difference in their ability to obtain typeable STR results after 19 months of storage (Kline et al. 2002).

Use of FTA paper simply involves adding a spot of blood to the paper and allowing the stain to dry. The cells are lysed upon contact with the paper and DNA from the white blood cells is immobilized within the matrix of the paper. A small punch of the paper is removed from the FTA card bloodstain and placed into a tube for washing. The bound DNA can then be purified by washing it with a solvent to remove heme and other inhibitors of the PCR reaction. This purification of the paper punch can be seen visually because as the paper is washed, the red color is removed with the supernatant. The clean punch is then added directly to the PCR reaction. Alternatively, some groups have performed a Chelex extraction on the FTA paper punch and used the supernant in the PCR reaction (Lorente et al. 1998, Kline et al. 2002).

A major advantage of FTA paper is that consistent results may be obtained without quantification. Furthermore the procedure may be automated on a robotic workstation (Belgrader and Marino 1997). For situations where multiple assays need to be run on the same sample, a bloodstained punch may be reused for sequential DNA amplifications and typing (Del Rio et al. 1996). Unfortunately, dry paper punches do not like to stay in their assigned tubes and due to static electricity can 'jump' between wells in a sample tray. Thus, this method is not as widely used today as was once envisioned. However, due to its preservation and storage capabilities, efforts have been made to use FTA cards for more widespread collection of crime scene evidence (Lorente et al. 2004).

Stuttering Simple Techniques to Help Control Your Stutter

Stuttering Simple Techniques to Help Control Your Stutter

Discover Simple Techniques to Help Control Your Stutter. Stuttering is annoying and embarrassing. If you or a member of your family stutters, you already know the impact it can have on your everyday life. Stuttering interferes with communication, and can make social situations very difficult. It can even be harmful to your school or business life.

Get My Free Ebook

Post a comment