Macromolecular Crystal Growth

Techshot offers two relevant categories of hardware: locker-sized environmental processing facilities and sample processing units also known as cassettes.

ADvanced Space Experiment Processor (ADSEP) facility

ADSEP processes three cassettes simultaneously via a 13-pin blind-mated DSUB connector, which passes control signals, power and data between the ADSEP command computer and internal cassette electronics. Each ADSEP compartment can be held at a different temperature if requested. A variety of operations can occur in Techshot smart experiment cassettes, within which several combinations of pumps and valves and other moving parts such as translating actuators and rotating reactor vessels can be operated by external commands from on-board programs or by operators on the ground.

BISEP Cassette

Each BISEP cassette contain two pairs of rotating plates with opposing cavities that, when activated on orbit, bring two liquids in contact with one another, for example precipitant and protein solutions for double-diffusion (aka liquid-liquid diffusion) crystal-growth experiments. It is also possible to perform dynamically controlled crystallizations, in which concentrations are deliberately raised by a second liquid-liquid exposure after nucleation and early crystal growth. Bulk mixing experiments can also be performed for the production of large numbers of uniform-sized crystals using the BISEP magnetic stirring system. The cavity volume is about 400 µL, so BISEP is suitable for research in which protein is abundant for industrial crystallization experiments. Unmodified BISEP plates accommodate 44 fluid pairs in each cassette. With its three processing compartments, the ADSEP facility processes 132 tests simultaneously.

Typical low-volume experiments using membrane-based methods (dialysis and osmotic dewatering) can be performed using single commercial cells or Techshot’s 3-position inserts that fit inside each BISEP well allowing up to 396 simultaneous crystallization trials in the ADSEP facility with a choice of dialysis, osmotic dewatering or vapor diffusion methods.

CellCult Cassette

Each CellCult cassette contains a 50 ml perfused rotating reactor vessel with controlled inlets and outlets, which is suitable for industrial crystallization experiments.