Matrivax Research & Development interview questions

The Lab director emailed me for an on site interview. There was no phone interview. The interview process involved meeting with the Director, Associate Director, Lab director and the staff which consisted of 3 people. The senior staff seemed very nice and talked cheerfully and explained about the position and the monotonous work which involved sacking the mice and performing ELISA. The director said they call the selected candidates for a second interview. However the junior staff was a bit weird and asked me the difference between an antibody and an antigen! Also, they were discussing with me that how could I kill mice if I am a vegetarian. It was totally weird and not at all professional.