Hybridizer is a hands-free denaturation and hybridization instrument designed for slide-based fluorescence and chromogenic in situ hybridization (FISH and CISH, respectively) on histology and cytology samples. The instrument allows for semi-automation of ISH by eliminating steps in the time-intensive manual procedure and can be integrated in laboratories working with the Dako Autostainer Plus and other Dako systems. Hybridizer Humidity Control Strips are specially designed for the Hybridizer instrument, and ensure a controlled high humidity during the in situ hybridization procedure. Hybridizer has a 12-slide capacity and heats and cools the slides through two temperature ranges with short ramp times. The system is easy to program for a wide range of protocols and is optimized for our DNA and PNA probes for FISH and CISH.