They claim it's 100% accurate which it probably is, but my problem with this product is the top portion of the dip stick. The color is never what it is on the chart. I find myself looking under every lamp to see if I can see it better. I always end up calling the company to ask what it means if the color isn't the same as their chart for negative, but it's also not the same color if there was an infection. I'd pass next time.Tiny Dancer