Experiences with HANGMAN: a macromolecular hanging drop vapor diffusion technique

A variant of the hanging drop vapor diffusion microtechnique is presented which uses an adhesive tape surface to simultaneously support protein droplets and seal reservoir solutions. The tape is supported on a teflon and plexiglas framework during setup of the experiment. The framework containing the protein solution droplets can be inverted over a standard tissue culture plate conyaining reservoirs of solutions for vapor phase equilibration. The time and cost of set up are reduced using the adhesive tape crystallization technique (HANGMAN). Up to 24 protein droplets can be inverted simultaneously using the tape with framework as opposed to individual inversion with coverslips. No pretreatment of tape or plates is required prior to experimental setup. There have been no effects observed on crystallization of proteins due to the adhesive. The adhesive surface shows resistance to a wide variety of chemicals commonly used for macromolecular crystallization. Protein crystals do not adhere to the hydrophobic adhesive surface and are easily removed for use in diffraction experiments.