Re: Closet biologists story

From: Robert J. Bradbury (
Date: Wed Jan 23 2002 - 13:21:38 MST

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.
> I know it would be a very dodgy setup, but would it be good enough to
> isolate prokaryotic dna, cut it up and gel it? what about eukaryotic?

Prokaryotic probably. Eukaryotic its going to depend on whether you
have a large sample to start with, are going to PCR amplify it or
need to isolate it from cultures. In that case you need to deal
with the CO2 incubator issue.


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