Dr. Pamela Ruegg concludes the series, 'Using On Farm Culture to Improve Mastitis Treatment,' with this episode about the most common problems for on-farm culture labs. Contamination during sample collection, handling or plating; failure to use quality control lab processes; and over-interpretation of bacterial growth just name a few. The value of any diagnostic test is based on the economic value of the intervention you make. If you do not use the culture results to make treatment or management decisions, the value of culturing is lost.