Templates
Buffer label maker
The buffer label's job is to stop someone using a 10× stock as a 1× working solution. Everything else on it is secondary.
Concentration is the field that matters
A 50× TAE stock and a 1× working solution are both clear, both in the same bottle, and both labelled “TAE” in most labs. The concentration multiplier deserves to be the most prominent thing on the label after the name — larger than the date, larger than the preparer.
The editor lets you set size, weight and colour per block, so the multiplier can be set in bold at a larger size than the rest of the label without turning the whole design into a poster. Colour is available too, and a red 50× is hard to misread — but colour is the first thing to disappear on a monochrome thermal printer, so it should reinforce a difference that is already legible in black.
Buffer-specific fields
- Concentration multiplier
- 1×, 10×, 50×. The single highest-value character on the label.
- pH and the temperature it was measured at
- Tris in particular shifts substantially with temperature — a Tris buffer adjusted to pH 8.0 at room temperature is not pH 8.0 at 4 °C. Record which one you set.
- Prepared date
- Buffers grow things. A date is what lets someone decide whether the faint haze at the bottom is worth worrying about.
- Additions
- Anything added after autoclaving — antibiotics, DTT, protease inhibitors — belongs on the label, because it is invisible and it expires faster than the buffer.
How much fits on a buffer bottle label
| Type size | Lines | Plex Sans | Barlow Condensed | Atkinson Hyperlegible | Plex Mono | Space Mono | Courier Prime |
|---|---|---|---|---|---|---|---|
| 4.5 pt | 19 | 80 | 111 | 81 | 64 | 63 | 64 |
| 5 pt | 17 | 72 | 100 | 73 | 58 | 56 | 58 |
| 6 pt | 14 | 60 | 83 | 60 | 48 | 47 | 48 |
| 7 pt | 12 | 51 | 71 | 52 | 41 | 40 | 41 |
| 8 pt | 10 | 45 | 62 | 45 | 36 | 35 | 36 |
| 10 pt | 8 | 36 | 50 | 36 | 29 | 28 | 29 |
Dilution instructions belong on the stock
A stock bottle is the right place to record how to get from it to the working solution, because that is where somebody stands when they need to know. “Dilute 1:50 in dH₂O” on a 50× stock removes an entire class of arithmetic error, and it costs one line.
The corollary is that a working solution should say what it was made from. A 1× bottle labelled only “TAE” leaves the question of whether it came from this lab's 50× stock or from a commercial 10× — which matters the moment a gel runs strangely.
Buffers that need more than the standard fields
- Anything with a reducing agent
- DTT and β-mercaptoethanol oxidise. The date added, not the date the buffer was made, is the one that governs whether it still works.
- Anything autoclaved
- Note it. An autoclaved buffer and a filter-sterilised one behave differently for some applications, and the bottle looks identical.
- Anything light-sensitive
- If it needs foil, say so on the label — the foil comes off and does not always go back.
- Anything with a shelf life measured in days
- This is the one case where an expiry date earns its place, because it is short enough to be a real constraint rather than a guess.
Common questions
- Should the pH go on a buffer label?
- Yes, with the temperature it was adjusted at where the buffer is temperature-sensitive. Tris shifts roughly −0.03 pH units per °C, so a Tris buffer set to 8.0 on the bench is meaningfully different in a cold room.
- How do I stop stock and working solutions being confused?
- Make the multiplier the second-largest thing on the label after the name, and keep the two in visually different places — a stock bottle with the multiplier on its own line reads differently from a working bottle at a glance, even upside down in a rack.
Open it in the editor
The editor loads at 63.5 × 38.1 mm with a worked example in place. It runs entirely in your browser: nothing you type is uploaded, and there is no account to make.
Last reviewed 2026-08-24.