Which safety practice should always be done at the beginning and the end of a microbiology lab? washing hands putting on safety gloves sweeping the floor securing loose clothing

Option A, Washing hand

Explanation:

Microbiology lab poses certain risks to the personnel working in it such as exposure to contagious culture, harmful chemicals, radioactive materials, etc.  

In such scenario, there are high chances of microbiologist or other  lab personnel getting infected with diseases or getting hurt by harmful chemicals and radiation.  

Thus there are certain mandatory safety guidelines which must be followed while working in microbiology lab of which washing hands with disinfectant soap on arriving and leaving the lab is the first instruction .

Hence, option A is correct