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
(Source)
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.

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DNA double helix
(Source)
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)
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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

    ReplyDelete