Re: Closet biologists story

From: Forrest Bishop (
Date: Wed Jan 23 2002 - 17:32:00 MST

----- Original Message -----
From: Robert J. Bradbury <>
To: <>
Sent: Wednesday, January 23, 2002 12:21 PM
Subject: Re: Closet biologists story

> On 24 Jan 2002, Alejandro Dubrovsky wrote:
> > > a) Water purification: $3000-5000
> > ouch. maybe buy the end product instead.
> Yep, I'm pretty sure Sigma sells it.
> > > b) -80 deg freezer: $3000-5000
> > is this definitely necessary? -15C won't do?
> If you want to keep your enzymes for long that is what
> is people suggest. I'm unsure if its "strictly"
> required. An alternative is an LN2 dewar but you
> have to keep it topped off.
> > > c) Sterilizer: $1000-$15000
> > alcohol won't do?
> Maybe. Combine it with a good long cook in the
> microwave and that would be better.
> > > d) Incubator: $2000-$5000
> > 2 grand for a heater!? are you serious? any disadvantage in using the
> > "use a lamp" method i read somewhere on the net?
> My microbiology lab used big cabinets with temperature
> controlled lamps, so that will clearly work. But if you
> want to do cell culture you have to control the CO2 level
> so you need something more sophisticated.
> > > e) Centrifuge(s): $1000-$7000
> > yes, i assume for isolating ribosomes, you'd want tens of thousands of
> > RPMs, but just to separate DNA, what would be the minimum RPM
> > requirement? wouldn't a souped up fan spun for a long time do? (only
> > half kidding)
> I don't know, I've never tried it. Perhaps a hacked CD-ROM drive.
> > > f) PCR apparatus: $2000-$4000
> > on the cheap side, i was thinking of using manpower: 95C tub, 60C tub,
> > 72C tub, move eppendorfs from one to the other when you think it's
> > appropiate. If this is too mindnumbing and feeling enterprising, grab
> > lego mindstorms, get it to do it for you.
> ROTFL. Boy that is a throwback approach, but it would probably work.
> > > g) Hood: $3000+
> > again, is it really necessary? (as opposed to, say, fan pointing out the
> > window)
> The problem is RNA and DNA contamination. You (and all the microorganisms
> in the air) are leaving traces all over the place. If you want good
> results you are going to need to avoid contamination. You might be
> able to get away with a hand constructed one, a blower and a UV lamp
> in it for sterilization when you aren't using it.

shade-tree inventing-
   I made a vertical-axis lathe a few years ago to produce composite molds for one part of a project (an electric ducted-fan camera
platform). The molds were for prototypes that would be part of an evolving design. A horizontal gap-bed lathe with a 24" swing would
have worked just fine, but these cost $thousands even used, in addition to locating, moving, tooling, and set up. To job this out
would have meant either a) contracting the molds at untold $thousands or b) many $hundreds and many trips back and forth to the
machine shop.
   The design revolves around a car wheel and a bicyle wheel driven by a belt. The car wheel was scrounged from a late-model
something at a junkyard. I wasn't able to check for bearing runout at the yard, so for $20.00 I bought it and hoped. The belt was
the only other thing I had to locate (the motor, step-pulley, etc. were laying around), as it is over 60" long. The wheel and motor
bracket were mounted on a scrap I-beam, with the bicycle wheel on top of the car wheel (I was in a hurry). It lit up first time, and
with care can I can make 4' diameter objects to about 10-thousandths- good enough for the ap. Total cost ~$50.00 and a day's work.
There was a shed roof over it that keep the leaves off.
  A centrifuge is practically the same thing, RPM and radius can be traded off.

  Most of the stuff on this list can be fabbed in a similar manner. Used restaurant equipment yards have stainless steel ovens and
proofing boxes that can be used for the incubator and sterilizing oven. The (restaurant) hood can be tigged up for a glove box
(maybe using marine fittings), SS counters and sinks can be had for pretty cheap. PCR is an exercise in Mondotronics. Maybe the -80
deg cooler can be a reverse-cycle argon or nitrogen-charged Stirling made from a car engine, using a standard freezer coil for
pre-cooling? CO2 monitors and metering valves would probably have to be store-bought. I don't know about the water, it depends on
the capacity and purity.


Forrest Bishop
Chairman, Institute of Atomic-Scale Engineering

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