We slip each bottle into a paper nickel coin tube or wrapper. We then cut out just enough to show the cell that we are using (1,2 or 3). This has worked very well for us. We also rotate a set of screeners every 8 hours so that they are not at room temperature all day.
We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.