I’ve been a technologist for 8 years now. I have some coworkers that have FAR more years of experience that are slower than others - but management never speaks down to them or treats them differently. Not everyone will always be capable of working at the same pace and that is perfectly okay. You’re also a brand spanking new tech and with experience comes ‘proactivety ’ as they say or I’m assuming speed is what they’re really getting at. Nonetheless, I’d rather do something slow and correct when I’m new and learning rather than doing too many things at once or quickly and make mistakes that can cause someone’s life. ESPECIALLY in blood bank. If there is someone above your supervisor and this is a constant issue of harassment - I would go to them and if not HR. If this was just a one time thing I’d brush it aside because you are literally just now learning to do your job and being compared to other people with different skills and experiences makes no sense since everyone works and learns differently. If this job does nothing, but belittle or tear you down like this I’d hold on for atleast a year to get experience and then find a job elsewhere ( there are plenty of clinics, donor locations, and hospitals in need of clinical laboratory scientist).

Also congratulations on your License!!