What is a sterile technique to transfer a bacteria culture in a broth from a culture tube to a cuvette?

Answer 1

Aseptic transfer is the name given to the procedures used by microbiologists to transfer living microbes from one place to another without contamination of the culture, the sterile medium, or the surroundings. You might find this website useful http://biology.fullerton.edu/courses/biol_302/Web/302labf99/aseptic.html
Hope it helps ;-)

Answer 2

Hoping that your question deals with procedure. The proper procedure would be to use a sterile medium to transfer from the the tube to the cuvette, i.e. a sterile cotton swab. Open the swab, stick it in the culture making sure to get some of the bacteria, and transfer to the other medium.