The creation of matter…


NanodropAT SCHOOL we learn that energy cannot be created or destroyed, it can only be converted. As matter is basically energy (revise E=mc2), then it follows that you cannot ‘create’ matter, it can only be converted.

Fortunately for us, we are lucky as a lab, for we have a Nanodrop that is able to achieve the impossible. The Nanodrop is a device used for measuring the concentration of biomolecules such as DNA, RNA and proteins, based upon the degree to which they absorb different wavelengths of light. All labs have such a device, but not all labs have the much lauded Nanodrop.

So when you’ve been labouring in the lab to purify DNA or protein, you then skip down to the Nanodrop in order to determine just how successful your preps have been. However, joy turns to dismay when upon clicking the special ‘Measure’ button on the computer software that powers the Nanodrop, the small value you see tells you that you have very little material; that in fact, you’ve wasted your time.

No longer though, because on our Nanodrop, if you press the magic ‘Measure’ button again, the value increases. In fact, each time you press the ‘Measure’ button, the value continues to grow. Keep doing this enough and you arrive at the kind of value that you were hoping for. With a few mere clicks of a keyboard we can quadruple the amount of DNA or RNA in our sample; an amazing feat given that there is no source of the raw materials needed to create the extra matter.

It really is the most impressive machine in the world ;-p

[update: following this post I was contacted by a representative of Thermo Fisher Scientific (formerly NanoDrop Technologies), to describe why we see the problem. The problem, it seems, is in the Chinese whispers by which one is taught to use the machine. It appears that one is only supposed to take one reading of any sample; repeated measures of the same sample show an an increase in absorbance over time as the 1-2 ul sample, being so small, evaporates – yielding a more concentrated sample. So there you go folks, quite logical really – you still can’t create matter; the search goes on.]


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