Saturday, 26 January 2013

Sometimes you have to be really careful labelling things.

There were two events at work today where I realised you have to be really careful when writing things down. the first was fairly innocent. I was using primers for PCR. One of the ones I wanted was "NJP082" but that's a squeeze to write on the top of an eppendorf so I settled for "82". Unfortunately I then discovered a "28" and I don't numerically categorize the diluted oligos...

I will try and remember to get a photo of this to prove the problem. For now, here is an example - keep in mind it's a lot smaller when on the top of a PCR tube.

I did a little bit of detective calligraphy and was able to work out which one was which but decided to make up a fresh dilution and underline it this time around.

The second issue was more problematic
in that I currently have 3 RNA interference (RNAi) * lines that have 6 letter codes. By some weird coincidence I'm using three distinct lines.

109602 - the gene I'm actually the most interested in at the moment and curious to see a phenotype.
106092 - the gene "baboon" that I have a feeling interacts with another gene and has a known phenotype.
106902 - a gene from a screen I did in the previous lab that gives a nice cell-cycle phenotype.

Maybe it's just me but those three numbers look awfully similar for me. I knew I had the first two so was pretty surprised to discover the third yesterday. At which point I had a strong feeling I'd only ever had two stocks with that kind of number. Closer inspection revealed that I don't actually have "109602" which is the most important one for me at the moment. What's happened is that when I checked to see if I'd ordered it I saw one of the others and my mind auto-corrected it in a numerical form of "typoglycemia". So now I know I don't have the RNAi line and that the Gal4 crosses I'd performed were for one of the other two. I'll set them up again and order the RNAi line. The bright side is that I'm probably 10 days away from having an actual mutant of the gene. The other thing is that I'm not getting really excited on Monday that my new gene of interest has a cell cycle/ TGF-Beta phenotype when it most likely does not.

Take home message - a scientist has to be alert at all times and should never let bias allow them to see what they want to see as opposed to what they are really seeing.

*RNAi is a method of knocking down the function of a gene. In this case you can control where and when in the fly the RNAi is expressed by choosing the correct promoter. I'm planning on doing a post to describe this properly but for an overview of RNA interference the wiki page is a decent starter.


  1. theres plenty of room on an epidorf to write njp082. you were just lazy

  2. Not when the marker pen is this big

  3. My old lab used to have a label printer in which you could lovingly create a detailed label in the a piece of paper the size of the little bits of paper from hole punchers.