Skip to main content

Assuming proper storage, how long can a blood sample be stored before it becomes unusable for BAC testing?

Los Angeles, CA |

First venipuncture on right arm failed to extract any blood. Therefore, the tech venipunctured left arm to collect blood sample for BAC testing. The sample was collected 5 months ago.

Attorney Answers 3


I would contact a local attorney for advice. Typically, most DUI attorneys hire their own expert to challenge blood evidence. There are a few national manufactures that produce the tubes wherein blood is stored for testing. These tubes have preservatives that claim to slow the process of contamination of the blood. However, there are always issues to challenge. Good luck.

Mark as helpful

3 lawyers agree


If the proper amount of preservative is present and the sample tube is undamaged, it can remain usable for years. Five months should be no problem.

Please understand that this is a general discussion of legal principles by a California lawyer and does not create an attorney/client relationship. It's impossible to give detailed, accurate advice based on a few sentences on a website (and you shouldn't provide too much specific information about your legal matter on a public forum like this site, anyway). You should always seek advice from an attorney licensed in your jurisdiction who can give you an informed opinion after reviewing all of the relevant information.

Mark as helpful

3 lawyers agree


You can hire an attorney.The attorney can retain a forensic toxicologist to challenge the protocol, retest the blood and formulate a viable defense.

Mark as helpful

2 lawyers agree

DUI topics

Top tips from attorneys

What others are asking

Can't find what you're looking for?

Post a free question on our public forum.

Ask a Question

- or -

Search for lawyers by reviews and ratings.

Find a Lawyer

Browse all legal topics