I have lost count of how many protocols I've seen, including those supposed to be professionally written (such as manuals that come with kits from well known brands, or methods sections of papers in respected journals), that outright fail to give unambiguous instructions. Some common examples are:
- Give centrifuge speed in RPM instead of RCF, and not say what rotor or centrifuge it is.
- Say to spin a sample at "maximum speed".
- Use subjective time periods, e.g. "incubate briefly" (is one minute brief enough or does it have to be five seconds?)
- Subjective quantities, such as "get a good amount of cells" (!!!)
- Give time ranges without explaining the consequences of the choice, such as "5-10 minutes" (is it 5 or 10? which one???).
- Say "mix well", without specifying if vortexing is okay.
- Say "mix well, don't vortex", and don't explain what mixing technique I'm supposed to use.
- Give urgent-sounding warnings, such as "don't touch the pellet!", without explaining what happens if I do it or how to fix it (do I need to start over? will I just get 5% lower yield?).
- Give urgent-sounding warning, without explaining how to actually heed the warning ("dry the pellet, but do not over-dry it!")
It is in fact extremely rare that I ever see a protocol that has none of these issues. It almost never happens.
It is extremely important that scientific results be reproducible, and it seems like you are opening yourself up to a lot of trouble with an ambiguous protocol. What if somebody fails to reproduce your results, not because your experiment wasn't legitimate, but simply because you left out some crucial detail from the protocol you gave them? You would look bad, and for no good reason.
So why is it so common for protocols to be ambiguous? Is there some nuance to this that escapes me, or do people just not care? How do you follow a protocol that left out crucial information so as to be impossible to follow? Or are you supposed to have amassed a sufficiently vast reservoir of practical knowledge that you can draw on it to "fill in the blanks" on the fly?