Most middle school science experiments require the student to take measurements of some sort, as a party of the "observation" stage of the scientific process. The measurement tools and equipment needed depends on the particular experiment, but basic and commonly used tools of measurement include scales and balance weights to measure mass and weight, clocks, stopwatches and counters to measure time, rulers and measuring tape to measure lengths and thermometers to measure temperature.
Magnifying equipment is critical for middle school science lab experiments. Perhaps most essential is the microscope. In addition to the microscope itself, however, one needs microscope slides, slide holders (to prevent fingerprints or smudges), slide holder cabinets and slide cleaner to sanitize equipment after use. Other common magnifying equipment includes magnifiers or magnifying glasses. These tools can be used outside the lab, such as in outdoor experiments and observations.
Middle school science labs should also be equipped with glassware (or plastic ware, depending on the grade level) for students to use for various experiments and projects. Common glassware includes beakers, bell jars, graduated cylinders, flasks, funnels and lid jars. In addition, glassware accessories --- such as droppers, stirrers and tubes --- are needed.
For all science and laboratory experiments, safety equipment is essential. Importantly, students should have protective eye wear for projects involving chemicals or projects with the potential for flying parts. Additionally, labs should be equipped with gloves to protect the skin, aprons to protect clothing and waste containers for biohazardous waste. A first-aid kit and eyewash solution should also be on hand.