- ToDo: Write me
Here's a good protocol.
- Single stranded DNA
- PEG (polyethylene glycol) 3350
- Lithium acetate
Single stranded DNA: Extract DNA from strawberries and boil for 5 minutes?
You can buy PEG in walgreens as MiraLAX, or the cheaper and more concentrated SmoothLax but it is 17g PEG 3350 in 17.9 fl oz of water so the concentration is probably too low. You can buy 500 g for $90 at p21. You can find it cheaper from non-lab suppliers but that's probably not sterile (and it should not be autoclaved). You need 400 uL 50% PEG for five transformations. I'm assuming that's per weight so 200 ug PEG.
Lithium acetate is available from sigma aldrich for $85 for 100g + shipping and for five transformation reactions you need only 0.0132 grams (100 uL 2 M lithium acetate and it is ~66 g per mol so 2 M would be 132 g per L)
Mercaptoethanol is $38 on p21 for 100 mL and only 4 uL is needed for 5 transformations.
Conclusion: The cost per reaction is close to zero assuming you don't contaminate your stock but the initial investment is around $250 (with tax and shipping). It's unclear if the companies will ship lithium acetate and mercaptoethanol to private individuals.
It is not recommended that you autoclave polyethylene glycol so you'd have to take care not to contaminate your stock. Probably a good idea to immediately split it into several smaller containers when it arrives.