Reality check and status update: I’m still a lab head, and I’m still poor.
But after knocking around in this new position for nearly three months, I have to admit that it’s rather good fun being poor. When you lack items that you’ve always taken for granted, you have to come up with all sorts of creative workarounds to do your experiments. I’m not exactly fashioning a Large Hadron Collider out of twigs, tin foil and gaffer tape, but until our next big grant gets funded, there are a few things I really need that we just can’t afford to buy outright.
As it’s Friday, I thought I’d share with you a few of our more ingenious inventions:
1. The poor man’s CO2 incubator:
As I described last time, we have to culture both sterile human cells, and human cells infected with bacteria. But we’ve got only one CO2 incubator, and the sterile human cells get priority. How then to culture the manky stuff? We can get around the CO2 problem by using media that’s buffered to be at the right pH under normal atmospheric conditions, and we have a regular dry incubator for growing bacteria on agar. What about the requirement for achieving over 90% humidity, though? In hunting around the piles of discarded junk we’ve been slowly getting rid of, I stumbled across a strange plastic container called a “Tommee Tippee”. I had no idea what it was at the time (now I know it’s a baby bottle sterilizer, bought in for someone else’s bizarre experiment a few years back), but without its inset, it looked perfect: a sealable container large enough to contain both a tissue culture plate and a bowl of sterilized water – all nestled on moist paper towels.
It worked a treat! All our cells were still alive and happy the next morning. Sorted.
Price: Hardware: FREE. Consumables (paper towels, water): Approx 5p/week.
2. The poor man’s lid:
When I arrived at the lab, I was bequeathed a pile of nearly-new stuff bought off a previous researcher’s grant – the woman had moved on to a non-research job. One of these was a water bath – without a lid. Had it been lost? When I went on the manufacturer’s website to see if I could order a replacement, I realized immediately why the previous researcher had not ordered one: it was sold separately, and it was nearly the same price as the bath itself. After another rummage in the Pile O’ JunkTM, I came up with an appropriately sized piece of plywood; after a nice coat of aluminum foil, it was good to go.
Result: a bit more prone to fungal infections than a real lid, and liable to tear, so we have to change the foil once a week. Still, preferable to sacrificing £150 quid!
Price: Hardware: FREE. Consumables (foil, to be replaced at weekly intervals): Approx 5p/week.
3. The poor man’s N2 tank (a cautionary tale):
OK, so liquid nitrogen is pretty damned cold: −321 °F, to be precise. You can’t just store your samples in tupperware or a Thermos flask. We had no recourse but to buy a proper 30 liter tank, but we went the second-hand route. This wasn’t easy: the UK is a very small country, and there is hardly anything out there. However, we eventually struck gold, purchasing our tank from a charming Yorkshireman called Steve, who was even nice enough to throw in a three-month guarantee, and a random set of storage canes for free.
All fine and dandy, except it soon became apparent that Steve hadn’t bothered to look inside the used tank before he shipped it off:
But no problem: after throwing away the ancient samples of Funky Monkey, we were ready to place a fill order with our friendly neighborhood BOC rep.
Price: Hardware: £400 + VAT (retail price, about £3,500). Consumables (nitrogen): Approx £6/week plus delivery. Free vials of dead monkey hepatocytes: Priceless.
4. The poor man’s shaking bacterial incubator:
Although originally a microbiology lab, the room and kit I inherited had no provision for growing broth cultures of bacteria. Traditionally, you need an incubator with a mechanism for shaking flasks and tubes with extreme vigor so that your bad-assed bugs are properly oxygenated and give high yields. This one was a real bitch to work out, but with a bit of trial and error, my colleague and I cobbled together the following little beaut of a solution.
1. Take tiny 37-degree benchtop incubator and put it on its side on top of a magnetic stir plate.
2. Open the small metal hatch (of completely unknown function) that is now on the ‘floor’ of the incubator, in contact with the stir plate.
3. Sterilize a 25 mL Erlemeyer flask with a magnetic flea inside it.
4. Add water for test run; pierce foil with thermometer to monitor internal temperature.
5. Place flask inside hole left by open hatch (almost a perfect fit, coincidentally) and switch on magnetic stirrer.
6. Turn on incubator and tweak the unmarked temperature dial until a stable 37°C is achieved.
Hypothesis: a vigorous flea-stir will create sufficient oxygenation for the bad-assed bug cultures.
Result: Unknown as of yet – still waiting for my consignment of tryptone and yeast to arrive. But we did manage to keep the test water temperature between 36 and 38°C over a weekend. Unknown as yet whether the incubator will work reliably long-term upended precariously on its side.
Price: Hardware: FREE. Consumables (water, flasks, fleas): FREE.
Next time: Manual PCR in three waterbaths?
I think not.