Saturday, February 2, 2013

Science Saturday 4.1: Tractor Beams & DNA

New year, new semester - it's time to jump start Science Saturday (yet again!)  We're only a month into 2013, but there have already been some awesome science developments this year.

Lil' Wesley Crusher with
his model tractor beam
Last year I mentioned the Star Trek inspired "needleless" injections, and this year scientists have brought another Star Trek tech to reality: a tractor beam! This new technique uses optical forces of light to transport and re-arrange microscopic particles. This requires a lot of energy to be transferred, so currently, a large object would result in over-heating.  But they believe it has great potential for medical applications at the cellular level.


DNA double helix
DNA is probably one of the most commonly recognized biological molecule with its unique double-stranded helix structure.  This helical shape is influenced by the interaction of the four nucleotides that code for our genetic material: adenine, guanine, cytosine, and thymine.  Yet recently, it has been demonstrated that there are areas of the DNA strand that may be saturated with the nucleotide base guanine.  These guanine-rich areas, specifically with an arrangement of four guanines, results in a square shaped structured termed a "G-quadraplex."  This four-stranded DNA structure is likely found in the telomere, located at the end of a chromosome which basically protects the genetic material from "fraying" at the ends.  Telomeres play a huge role in cell division, and therefore are important to cancers (which is unlimited cell division).  The discovery of the G-quadraplex only adds more questions to answer, but is a great start toward new discoveries.

G-quadraplex structure (Source)

Speaking of DNA, scientists have been able to used the special coding abilities of the four nucleotide bases mentioned above as storage of digital media, including a color photo, 26 seconds of Martin Luther King Jr.'s "I Have a Dream" speech, and all of Shakespeares sonnets. While digital media is encoded in binary, using 0's and 1's, DNA-based storage relies on encoding in trinary. They accomplish this by using one of the nucleotide bases as a "spacer" between groups of the three other bases.  While it is not perfect, it has the potential to be used as a long-term storage process, since DNA will last longer than any dated media technology such as tape or disk.

DNA storage process (Source)

1 comment:

  1. Fascinating!

    (I am still waiting for our clinics to get those needless shots!!)

    Lily-thinking thoughts