ELISA plate longevity - (Nov/22/2011 )

Has anyone done a longevity study on their in house ELISA plates?

I have tried protecting with sucrose, trehalose, storing at 4c and 37c,desiccating vs. non desiccating and working with different type of preservatives in my diluent buffer.

after one week with these variables, the results at 450nm dropped from 1.2 to 7.0.

Has anyone tried anything that I haven't mention?

There's alot of web resources on this subject and many commercial products available a couple of examples below:

http://www.ebiotrade.com/buyf/productsf/biodesign/elisapcs.htm

http://www.bionity.com/en/whitepapers/82865/eternal-shelf-life-for-elisa.html

In my experience, I stay away from precoated and dried plates and find that overnight coating at 4 degrees results in higher precision, with uniformity assessments giving CVs of 5% less than precoated and dried approaches.

Let us know what you find, and I would be interested to know if you can get similar uniformity CVs (all 96 wells mid curve concentration) with freshly coated vs dried.

There are tooo many commercial companies to name that have dried ab or ag coated wells/plates that are stable for one year! (at 4C or at RT) This is a fairly common problem and you have examined some of the common components used to extend shelf life.

Also, there are many companies such as Cando, Surmodics, East Coast Biologicals, etc etc that make 'stabilizing/coating/blocking' solutions. You can certainly get samples or purchase some to try.

I would continue with your sucrose,trehalose sugars and also check out Corn Syrup Solids as well. You should also have some BSA or blocking protein in there as well.

The key is:
1 Coat your plate. Decant as normal
2. Block your plate and incorporate the stablizer. Allow to sit at RT for 30 min to 1 hr. Decant and dry inverted. (do not wash).
Place the plates in plastic bag or foil pouch with dessicant and seal; store at 4C or RT.

Give this a try. FYI there may be an initial loss of signal but it should plateau.