Micro-staining microbes: An alternative to traditional staining of microbiological specimens using microliter volumes of reagents

Microbial staining techniques are widely employed in clinical and academic laboratories for classifying and identifying microorganisms derived from clinical, food and environmental samples. Staining allows for the rapid visualization and determination of many morphological characteristics of microorganisms, used for their identification and classification. Over the past century, staining techniques such as the Gram stain, the Capsule stain, the Acid-fast stain and the Endospore stain, have seen few advances, and manual staining remains the gold standard. Typical instructions for these staining procedures recommend 'flooding' glass slides with milliliter volumes of dye, resulting in large volumes of hazardous waste. Here we present micro-staining, a simple alternative to flooding that utilizes microliter volumes of dye. Micro-staining minimizes the volume of waste generated, leads to significant cost savings for the laboratory, requires limited training, and produces results with equivalent quality to traditional stains.