I'm wondering if plasma glucose can be measured with a regular glucose meter and strips like this. I know these meters are normally used to measure whole blood glucose, but can they measure plasma glucose levels as well?
Based on experience with one commercially available retail glucose meter it is my belief that the glucose content of a fairly wide range of water-based liquids can be measured. These meters should always be checked against more reliable systems but I think they give fairly consistent and correct results.
If the meter uses absorbent strips which transfer liquids by capillary action to a measuring system the system is unlikely to be affected by (for example) suspended proteins. There may be solutes that would skew the reading but probably not those contained in blood. As per Chris's comment, any liquid subset of whole blood should not be a problem for one of these meters, with the caveat that they may be cheaply made and require a little practice to get consistent results.