Splitting a vial for two laboratories: how to do it without ruining both

Splitting a vial for two laboratories: how to do it without ruining both — setting out what I have, and where I think it stops being reliable.

A logistics question, since the answers here are usually better than anywhere else I have looked.

Parcel despatched 19 days ago, tracking last updated 7 days ago at a customs facility, no further movement. Cold pack included at despatch.

Two questions. First, at what point is this genuinely a problem rather than an ordinary delay? Second, if it does arrive, what is the actual decision process for assessing it, as opposed to the two extremes people usually offer?

This follows post #8 rather than contradicting it.

VendorInvestigate: documentation and supplier-practice review. Reviews paperwork rather than vials. Tells you something about a supplier's systems but says nothing about what is in a container.

Coming back to post #23, because the follow-up matters more than the original answer.

VendorInvestigate: documentation and supplier-practice review. Reviews paperwork rather than vials. Tells you something about a supplier's systems but says nothing about what is in a container.

Repeat testing: if you want to verify the same lot a second time, testing with a different service strengthens the conclusion. Testing with the same service verifies reproducibility but uses the same method.

post #41 answers the question as asked. The question underneath it is different.

Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.

On post #50 — agreed on the reasoning, with one qualification.

How to submit a sample: contact the service directly. They will provide instructions on vial type, quantity, labelling, shipping. Following their instructions exactly ensures results are interpretable.

Blind sampling: submitting without the laboratory or seller knowing the source removes the two easiest ways for a result to be shaped: selective submission and selective reporting. The extra effort is worth it.

Repeat testing: if you want to verify the same lot a second time, testing with a different service strengthens the conclusion. Testing with the same service verifies reproducibility but uses the same method.