An aspect of the disclosure is a method and device for the detection of antibiotics in a sample. Embodiments include a microbial culture with growth indicators and sensitivity adjustment reagents. Adjustment reagents include a variety of antibiotic binders that can be added to microbial culture to reduce sensitivity to certain antibiotics. Some embodiments include multiple buffers with a variety of pKa ranges. Some embodiments also include a complete self-contained apparatus for sampling and testing.