Physiological Saline Testing

Overview

This page is a work in progress that will describe the basic methods and plan to test device bio-proofing in saline solutions.

Solutions

Phosphate Buffered Saline (PBS)

Overview

There are plenty of resources out there that provide a pretty good overview of the basics of Phosphate Buffered Saline. It's safe to consider it one of the very valuable workhorses of life science labs. It's completely compatible with cell cultures and it's relatively easy to make and handle.

Example Formulation Materials (1 liter)

• sodium chloride (8 g)
• potassium chloride (0.2 g)
• sodium phosphate, dibasic (1.15 g)
• potassium phosphate, monobasic (0.2 g)
• distilled or double distilled water (1 L)

There are other formulations available if, for example, we want to do a batch of 10X PBS to store and dilute as needed.

Additional Materials Required

• a good balance to weigh the materials on
• glassware for measurement and storage
• pH strips are do-able, but a pH meter would be preferred
  • buy, buy, or build?

Storage Requirements

If the solution isn't going to be used soon after making it, it should be stored refrigerated and sealed securely to keep it sterile. When removing it from storage, it should probably be checked for precipitation (especially if it's something like a 10X concentration).

Possible Vendors

If sourcing the materials and tools needed turns out to be a hassle there is always the possibility of purchasing the solution in liquid (concentrate or unconcentrated) or tablet forms. This may be slightly less fun but it does come with additional quality guarantees.

• Sigma-Aldrich (http://www.sigmaaldrich.com/united-states.html)
• Invitrogen (http://products.invitrogen.com/ivgn/product/18912014)
• Amresco (http://www.amresco-inc.com/)