100 Ideas

"One a year" - A pre-retrospective: 2008-2108

Culturing bioluminescent microbes, part 1

30-sec shutter overlay

I’ve been fascinated by bioluminescence from the first time I saw pictures of deep-sea angler fish. Since then, I’ve seen dozens of live bioluminescent creatures at the Boston aquarium and cultured E. coli expressing the LuxCDABE operon from Vibrio fischeri in Tom Knight’s lab.

It surprisingly easy to grow bioluminescent microbes. I’ve found a couple of undergraduate-level protocols online for isolating marine Vibrio species from fresh squid. I’m currently in the middle of my second attempt at isolation. These are my notes so far. I’ve adapted this Basic Protocol for Isolating Bioluminescent microbes for use in my kitchen.

I’m using food-grade agar I got from a food-hacking friend, powdered chocolate jello (I ran out of powdered agar), Baking Soda instead of CaCO3 (chalk), and canned tuna water instead of powdered LB broth (hope it doesn’t have preservatives in it).

13 Jan 2010

18:30 Got fresh, “uncleaned” squid from New Deal Fish Market in Union Square: $2.50

18:55: got 1L gatorade

Added 1/2 teaspoon of sea salt to the empty gatorade bottle

22:00 cut squid head in 1/2, added to tap water in gatorade bottle

14 Jan 2010

22:00 It GLOWS! wow!

took pictures with ad-hoc cardboard camera frame; cutting gatorade bottle in half (squid now in what resembles a petri dish with 8-inch tall walls)

Added 15 mL of Jeff’s Food-Grade agar to 450 mL of water; not enough? Still liquid. (only have a 15 mL falcon tube, not a scale).

Boiling the agar liquid in a water bath. Will add Jiffy CornMeal to supplement.

22:25 agar solution at 175 C. Cools to a mildly viscous liquid.

22:30 adding 15 mL chocolate JELLO

How many grams is 15 mL of agar powder? 0.34 g / cm^3 (http://www.wolframalpha.com/input/?i=15+mL+Agar) 15 mL ~ 5g.

How about Jello? 1.1 g / cm^3 (http://www.wolframalpha.com/input/?i=15+mL+Jello) 15 mL ~ 17g

Most LB plate protocols call for 15 grams of agar powder / Liter. I started with 5g (15 mL) in 450 mL of water. So I was 2/3 short.

It turns out 15 mL Jello + 15 mL agar in 450 mL boiling water solidifies into something approximating an agar plate. I’m adding 2.5 mL more Jello to thicken it a bit.

Other ingredients of recommended for Luminescent Agar plates (per 450 mL H2O):

  • 2.5 g CaCO3 (NaHCO3 is 2.173 g/cm3; and I’m going to substitute it. Added ~ 1g)
  • 5 g Glycerol (left it at sprout)
  • 15 g NaCl (2.165 g/cm3, added 4 mL; ~ 8.66 g)
  • 4 g “dehydrated Nutrient Broth” (I’m using a teaspoon of liquid from a can of tuna)

0:00 15 Jan 2010 Poured “Luminescent Chocolate Agar”

0:30 poked bright blue bioluminescent patches on the squid carcass with a toothpick and streaked them out on the choco-agar.

Colophon

I'm Mac Cowell. I'm an amateur biologist. I'm a part of diybio.org. I'm interested in synthetic biology and refactoring and reengineering existing biological tools and techniques to be cheaper, easier, safer, and more accessible.

Syndicate

August 19th 2009
Tags: Uncategorized

No Comments

The Upshot of Diagnostic Kits

As part of the interview process, Carolina Rossini asked me to write a short report on "The Problems of Patents on Diagnostic Testing Kits" (pdf). Later that summer, I read Steven Levy's "Hackers: The Heros of the Computer Revolution." Now I've started to see an analogy between the tools used by nascent ...
June 26th 2009
Tags: articles

No Comments

The Web Ecology Project pub 01

Over the last few weeks I've been putting my shoulder into ruby, twitter analytics, basic statistics, and visualization along with the fine young minds of the nascent Web Ecology Project. One of the first things we looked at was the trending terms on twitter; Specifically, for every day over the ...
May 27th 2009
Tags: DIYbio, Garage Metagenomics

No Comments

Building an example BioWeatherMap dataset

I want to make an example "BioWeatherMap" based on existing metagenomic data, so I'm looking for a dataset of 16s ribosomal dna (rDNA) sampled from tens or hundreds of environmental locations. First I'd start by creating a simple map rom the basic data (sequences + location) - something like ...
May 25th 2009
Tags: Garage Metagenomics

One Comment

Problem: sequencing a heterologous mix of 16s PCR products

Possible solution: Use gel electrophoresis to separate the DNAs. Temperature Gradient Gel Electrophoresis (TGGE) and Denaturing Gradient Gel Electrophoresis (DGGE) DGGE of small ribosomal subunit coding genes was first described by Gerard Muyzer, while he was Post-doc at Leiden University, and has become a widely used technique in microbial ecology. ...
May 20th 2009
Tags: ideas

One Comment

better web history

I rarely refer to my web browser's history. It has a low signal to noise. It seems like the most literal implementation of the notion of "browsing history". It has no notion of what I was looking for, why I was visiting a page, and if I ...

Search

The archives run deep. Feel free to search older content using topic keywords.