bacterium
beaker
biology
biotechnology
blood
blue
caucasian
chemist
chemistry
color image
contemporary
discovery
doctor
expertise
face mask
health care and medicine
horizontal
hospital
hygiene
lab coat
laboratory
medical exam
medical test
medicine
men
microbiology
nurse
occupation
people
photography
professional occupation
research
sample
science
scientific experiment
scientist
student
technology
tube
tubing
two people
virus
white
women
working