Theoretically, the fastest way to get your foot in the door is "Route 4". I feel like Route 4 was created to more easily facilitate grandfathering in older techs, but nonetheless, it does exist and is legitimate. You would need to get "three years of full time acceptable clinical experience (Acceptable Clinical Laboratory Accreditation: CMS CLIA certificate of registration, compliance, accreditation; OR JCI accreditation; OR Accreditation under ISO 15189.) in blood banking, chemistry, hematology, microbiology, immunology, and urinalysis/body fluids in an accredited laboratory", and simultaneously simply go back and complete freshmen year Biology and Chemistry postbaccheloreate without lab (6 credit hours in Biology and 6 credit hours in Chemistry).

The challenge here of course, is to convince an accredited laboratory to hire you on full-time and rotate you through the relevant departments, with no experience, training, or relevant education. But if somehow you can pull strings and land that job, and your director can testify to your lab's accredditation and your experience, yes theoretically you can sit for the MLT BOC via Route 4. After being hired on as a full-time MLT, it is much easier to go to MLS via Route 2, which would require picking up 10 more credit hours in both Chemistry and Biology and at least one semester of Ochem/Biochem.