microfractionation of human tears

April 23rd 2011 04:43 pm

microfractionation of human tears tumb

This is from the GE Life Sciences handbook Gel Filtration: Principles and Methods. It is shown on page 45 with no context whatsoever, other than potential applications of their fancy technology. For non-biologists, this is a so-called gel filtration trace, which is a technique used to separate a mixture of proteins based on their size. The peaks (which range from the big sharp one at ~45 minutes to the smaller lumpy things around 20 minutes) correspond to the proteins that are present in tears. The most basic interpretation of this figure is that there are at least 6 or so proteins that make up the majority of those found in tears. But there are so many more questions!

  1. What are these different proteins?
  2. Whose tears were these?
  3. How were the tears obtained? Did someone go to a funeral with a test tube and collect tears of grief? Did they stab somebody for tears of pain? Perhaps an olympic athlete donated tears of joy after winning the javelin throw.
  4. Would the protein components of the tears be different depending on whether they are tears of joy/sorrow/pain?
  5. Why is the buffer so salty (0.5M NaCl) and acidic (pH 5.3)? Are tear proteins only happy under salty acidic conditions?

It would not be hard to answer some of these questions. For #1, I’m thinking that you could take a few tears (probably wouldn’t need very many), TCA precipitate all the proteins, perform a trypsin digest, then identify them using peptide mass fingerprint analysis.

#4 could be a Nobel-prize winning experiment. Say for example that with joy tears, the peak at 65 minutes goes way up. You have now identified the Hope protein. I’ll go so far as to name it Hopease.

Posted by dylan under humans | 7 Comments »

7 Responses to “microfractionation of human tears”

  1. sam responded on 24 Apr 2011 at 6:37 am #

    it reminds me of this: http://blog.everydayscientist.com/?p=104


  2. sam responded on 24 Apr 2011 at 6:37 am #

    and your earwax post a few years back…

  3. Jered Floyd responded on 24 Apr 2011 at 9:59 pm #

    Some research on #4 has already been done. See http://www.thenakedscientists.com/forum/index.php?topic=19782

  4. dylan responded on 29 Apr 2011 at 5:04 pm #

    Jered, that’s friggin amazing, thanks for the link. Sam, why did it have to be an albino rabbit?

  5. james responded on 13 May 2011 at 5:54 pm #

    people still read this?

  6. FleaTamer responded on 03 Jun 2011 at 1:10 pm #

    One of the major proteins will be lysozyme – a glycosidase which cleaves the saccahriaride chains in bacterial peptidoglycans


  7. Patch responded on 02 Mar 2014 at 12:03 pm #

    They could well have got the tears from an athlete who has just lost the javelin-catch.

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