BugSpray (TM): Science Marches On   Leave a comment

Brian coated


Our lab has four instruments of, ostensibly, the same make but with post-manufacture modifications that make each one fairly unique. As a form of short-hand for describing them we have assigned each with the name of one of the Beatles. This started when we started referring to one as “Ringo” because it was purchased 2nd hand from the University of Liverpool. The most exotically modified one became “George,” while the one that produces less but lays claim to being the best of the bunch is now, of course, “John.” “Paul” is actually the most productive if, at the same time, the least interesting of the machines.

With the Beatles already represented in the lab, I spotted what was our most likely candidate for the Fifth Beatle, or Beetle, in this case, which came to be known as Brian (after the late Mr. Epstein). To avoid problems with patient identification let me assure all and sundry that Brian is not, in fact, his real name — that would be Eric (Clapton) — but is an acronym for Beetle Reinforced Ionisation And Nebulisation (the nebulisation part is future work which will involve shoving an air hose up his jacksie to pressurise the flow).


Brian 3


All new work and equipment not covered by earlier Risk Assessments requires that a new one be written, submitted to a Safety Officer for editing and approval, and then promulgated amongst the users. Brainstorming the possible risks resulted in several salient points, vis:

-> Capturing the device requires squatting and stealth and might give one the willies.
-> Improper dessication might result in the device exploding in vacuo.
-> Do not let the cat see it if there is a cat in the lab: you’ll find your emitter puked up under one of the instruments.

Using standard forms as in previous RA’s, here are extracts from the version sent in so that work might commence here at the University of Swindon:



Risk Assessment BugSpray page 1

Risk Assessment BugSpray page 2 detail

Risk Assessment BugSpray page 3

Risk Assessment BugSpray page 4


The actual prep followed this RA faithfully. The emitter was sacrificed by EtAc asphyxiation and harvested as per entomological standards then sealed in Tupperware with anhydrous Calcium Carbonate dessicant (DrieRite™) for 4 weeks to dessicate.




Brian dessication


Space in a gold sputter coater was available alongside glass capillaries that needed a conductive surface application and soon our BESI (Beatle ElectroSpray Ionisation) source was ready for testing:



gold coater


Brian coated iso


The following slides were captured from the positioning camera near the entrance cone to the mass spectrometer vacuüm system. First, there is an early attempt at positioning Brian:



Brian in position


Next, we see Brian laid on his back as the original position produced what can scientifically accurately described as Fuck-All spray. In this shot you can make out the development of a Taylor cone of the droplet applied to the Bi-lateral Mandibular Emitters:


Brian upside down with Avidin


As the hours wore on, the sprayer’s efficacy deteriorated and higher voltages were applied eventually resulting in corona discharge (which was bright blue and streamed across the cadaver for several seconds much more impressively than this screen capture):



Brian alight


But, I guess the proof is in the pudding. Fifteen years ago, most people would have shit themselves if they could get a spectrum of even one of these three proteins (which are, in turn, intact complexes of smaller proteins). Our little friend here yielded a splendid example of a wide dynamic range mass spectrum:



BugSpray mix spectrum

Okay, I admit for the scientists out there that this spectrum is a little dirty (especially at the low m/z end of the scale), the peaks are a bit wider than most you see around, and although these are somewhat challenging samples they are admittedly some of the easier protein complexes to spray. Let me respectfully reply,




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