respirometer-fu

A Different Sort of Weapon for My Arsenal

Do you remember all the fun I had with the human female and her Prep Staff and the pesky respirometers that arrived broken and that wouldn’t work?  Well, the semester has rolled around to that lab again, and I decided I wasn’t done making lives miserable and bringing shame upon Lower Division Biology.  (When things don’t work, complaints find their way up to the highest levels of admin and the repercussions flow downhill to the human female and her crew.)

Since the last time these apparatuses were used, the Prep Staff has been hard at work trying to find a replacement for the glass bean tubes that break and the rubber stoppers that won’t stay in.  They’ve settled on poking a hole in a screw-top centrifuge tube and using that.  The hole has to be sealed up, though, or the thing won’t work.  Today they’re working on that problem  And since I hear that the solution involves a “gun,” I demand to be involved!

This is the gun.

hotgluegun

I’m not so sure how great a weapon this is.  It appears to run on electricity and requires to be plugged in, which would severely limit its usefulness in battle.  What sort of projectiles does it fire?

Sleipnir’s snot-balls!  It doesn’t actually fire anything!  Instead, it produces a stream of molten goo which is very, very sticky.  It dries and cools to something rigid, though.

(poke, poke, poke) Perhaps one is meant to adhere one’s enemies to one spot–and then dispatch them by some other means.

hotgluegun2

I must say I’m not impressed, and as a Frost Giant, I view anything that works with heat with more than bit of trepidation.

And then there’s the little matter of the stretchy, clingy, stringy THINGIES it leaves everywhere…

hotgluegunstrings

Nope.  Not impressed at all.  Although I think I could probably have fun decorating the human female’s work space with this stuff.  She’s certainly making enough of it, putting huge dollops of the goopy stuff on the inside and outside of the respirometer lids.

Ewww!  Ouch!  I think I’ve discovered what this weapon is good for.

hotglueblister1

And there’s a second nice blister on her other forefinger.

I take it back.  I LOVE this thing!

>|: [

 

Advertisements

Remember the Respirometers? Part II: I Called It

Did you think the stoppers were the only bits of the respirometers I worked my mischief on?  Pfft!  It’s like you don’t even know me!

respirometers2

As I predicted, it was a fiasco.  Admittedly, the prediction doesn’t count, because I contributed to the fiasco, but that does not diminish the fun I had watching the human female and her minions scurry, struggle and curse.

First the cantankerous instruments got filled with a small amount of bluish-purple indicator fluid–a simple mix of glycerol and dye.  Never mind the fussy business of getting it equal in all the various tubes, I saw to it that it kept making air bubbles (which interferes with getting a reading) and that the students let their reactions go too long, letting the fluid go up and over into the dry beans or the live, respiring beans.  The Prep Staff was kept hopping, replacing wasted fluid in all the rooms all the time.

And the fluid was wet enough to wake the dry beans up and start respiring, which played merry Hel with the results.

Then there were the test tubes.  They were filled with a bit of cotton, a plastic platform (just visible in the left of the picture below), and then either dry beans or soaked, living beans.

respirometer-broken-tube

I had a hand in choosing the platforms for the respirometers.  I made sure that they weren’t all exactly alike.  Some were just a smidge larger in diameter.  Prep staff broke four tubes just loading the platforms in.  The students broke a further five by pressing too hard, trying to jam the rubber stoppers in.  Prep staff spent all week cannibalizing spare units for parts.

Then there were the bits of tubing.  The rigid ones turned out to be plastic,  not glass, but you know what?  They break just as easily!

respirometer-broken

*Tink!*  Just like that.  We went through a lot of those.

Unfortunately, the human female put on her Science Thinking Cap and there may be work-arounds for next semester.

respirometer

A plastic 50-milliliter graduated cylinder is going to fit as a replacement for the test tubes.  The rig is even more stable afterwards, as the cylinders have big “feet.”  Prep Staff will probably have to cut them all off below the spout so the stoppers will fit, though.

And the breaky little graduated tubes?  Close inspection shows that they are cut from 1-milliliter plastic serological pipettes.

respirometer2

The human female discovered a five-kilo box of the things in a storage cupboard in one of the prep rooms.  They’ll have to cut those to fit, too.

In short, they can actually improve the basic apparatus!

Am I discouraged?  Disheartened?  Hel, no!  They’ll probably try to use a Dremel motorized cutting tool to do both modifications, and no one ever uses one of those without a mishap or three.  It’ll be broken cutting wheels, sharp edges, slips, sparks, and that annoying, high-pitched “nnnnnyeh, nnnnyeh, nnnnnnyeh” noise that’ll give everyone a screaming headache.

I can work with that.

>|: [

Remember the Respirometers? Part I: My Mischief is Unstopp(er)able

Remember the respirometers?  The ones that arrived largely broken or incomplete?  Recently the students did the lab exercise that uses them.   Making things break wasn’t the only fun I had with the respirometers.  Pfft!  I am much more multimischievous than that!

First, the human female and her Prep Staff had to assemble them for use.

respirometers2

A word of explanation:  The respiration experiment measures the gases given off by the germinating beans in one tube, compared to the not-doing-anything that goes on in the tube with the dry beans.  For it all to work, all the components must be air-tight.

stopper5

When the instruments came from the manufacturer, they had no stoppers at all.  That little goof was immediately obvious, so the professor whose project this experiment is demanded that some be sent.

I helped the manufacturer pick out the stoppers to include, so they sent nice, white ones.  Which all proved to be too small to actually seal the test tubes.  Not only that, but they were made of some weird substance that left chalky dust all over everything.

The professor caught this mistake soon after the white stoppers arrived and demanded that the manufacturer supply stoppers that would actually work.

So the black ones arrived.

Which was all well and good, except that they didn’t have any holes.  Holes are a bit critical for this application, but a pain in the neck to drill, so the professor shipped them all back, saying, “I’m not doing this, YOU do it.”

Let us examine the stoppers which were ultimately received and which the science nerds are using today.

Sturdy.  They appear to be made out of the appropriate type of rubber.

stopper4

Odd, though.  Every other black rubber stopper she’s ever seen has the size number on the top.  It’s on the bottom of these, so the human female is automatically suspicious.

Not to mention the little stray fringey bits around the edges.  All in all, a substandard molding job.

Thor’s bitty ball-peen!  They are not all the same size, either!

stopper3

Nor are the holes!  In assembling the respirometers for use, some bits of tubing are going in neatly and sweetly, while some are so hard to insert that the human female and her minions are getting cramped and bruised fingers from trying to jam them all the way in.  Slicking stopper holes up with glycerin isn’t entirely solving the problem–it just makes everything slippery and hard to grip.  Eehehehe!  Sometimes I’m so naughty I crack myself up!

They are partway through the assembly and the human female has just discovered that….TA DA! 

stopper2

Not all of them are completely drilled!!

See?!  Little pucks of rubber that have to be poked out with a probe or small paintbrush handle.

stopper1

Uh, oh!  I am laughing so hard I think I may have hurt myself, and Prep Staff is starting to mutter about “acetone” again.

I think I shall beat a strategic retreat.

>|: [