I am a Victor 2 Spectrophotometer

Published on 31/10/2007

Two days ago, one of my colleagues asked me if I would have dressed up in a costume for Halloween. If I were an American, which means I’d feel the need to celebrate it in some way, I think I’d dress like HAL 9000, from recently-mentioned “2001: A Space Odyssey”. That’d be a very cheap and simple costume: all you need is a huge, black, cardboard box (I could find plenty of them at the chemist’s where I used to work, although, of course, I’d have to paint them), with a red, glowing spot in front. Then you start to make intelligent remarks, showing off your (intellectual) superiority, with a calm, monotonous voice. Not the best way of making friends at parties, I’ll admit…

However, because I’m Italian, today is just Wednesday, and I usually don’t wear costumes on Wednesday. Still, yesterday I told my supervisor I was going to the student office of my faculty to hand in a stupid certificate, and she said I had to be quick because “at 11 o’clock, we’ve to visit Victor2.” Suddenly, the image of HAL 9000 popped into my head. Were we going to meet an intelligent machine, which we had to convince it was reasonable and logic for us to use it? Is Victor 2, the stepbrother of HAL? Would Victor2 eventually kill me, if I accidentally made a mistake and ruined the assay? These were some of the eerie things I was considering while walking in a cold rain, which reminded me more of Blade Runner rather than 2001.
“Hi, Victor 2”
“Good morning. You’re late: problems with the weather?”
“Yes, a bit.”
“Shall we start? I have a busy day, as you can see from the dairy on the shelf.”
“Right. We have to carry out a cytotoxicity assay and we’ve chosen to use MTT. So, plainly, we’d like to start measuring absorbance as soon as we receive the tetrazolium bromide. Thing is, neither of us has ever used this particular technique, so, we’ll have to work out a standard protocol, before we could really start the experiment.”
“The MTT assay is, indeed, an excellent option: you dissolve a yellow tetrazolium in your medium and then those cells that are still metabolically active reduce it to its purple formazan derivative with mitochondrial dehydrogenases, yielding crystals.
The formazan precipitates and must be dissolved: for this task, you can employ either an acidic, alcoholic solution (generally a 0.1 M HCl in isopropanol) or, as people often do here, 0.01 M HCl in 10% SDS. Then you’ll need me so what’s what: the absorbance should be measured at 570 nm, but my instructor built me with a 595 nm filter. No one here has ever had any problem with that. There is another small issue: theoretically, you should subtract a background absorbance measured at 690 or 650 nm, but, again, my instructor didn’t fit me with a filter that allows you to read at that wavelength. However, there is a smart way of solving this: do not put cells in a well of your plate so that it will serve as reagent blank. What kind of plate do you want to use?”
“A 96-wells one.”
“The average volume of cells per well is 100 μL. To determine the best number of cells for the assay, draw first a calibration curve at least in duplicate and select the value that gives you an absorbance between 0.75 and 1.2.”
“Right. So, I think we’ll meet again next week, to test which concentration of cells is the best for the job in hand, ok?”
“I am putting myself to the fullest possible use, which is all I think that any conscious entity can ever hope to do.”
“Uh…”


Comments

  1. psi*psi
    31/10/2007 | 11:24

    Yay, thiazole ring!
    (my favorite cute little heterocycle. thiazole chemistry is a BITCH, though)

  2. Uncle Al
    31/10/2007 | 12:10

    1) four dozen baby bottle rubber nipples, with flanges.
    2) tube of silicone colosotomy bag contact adhesive.
    4) lab coat or wizard's cape (optional).
    3) http://www.mazepath.com/uncleal/nipman.jpg

    Gently wipe skin with rubbing alcohol-wetted tissue to remove sebum. One flange is the adhesive stamp. Use it to stamp your skin with rings of adhesive, then let dry. Meanwhile apply a thin coating of adhesive to the other nipple flanges and let dry. Touch flange to ring and it seats for 8+ hours.

    SAFETY WARNING! If you do not get the adhesive off that night your beard grows through it by morning. This is OK biologically but is a composite structure engineering disaster.

  3. milkshake
    01/11/2007 | 17:05

    I like this message from an instrument:

    "Fatal error #4023. The operator will be executed."

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