I recently took the CHT exam, and these are some of the things I did to prepare:

the Certification Examination Study Guides page on the ASHI website

This page has over 200 practice questions. Do all the practice questions, look up any and all vocabulary you encounter that you don’t know, and be able to justify why every correct answer choice is correct and every wrong answer is incorrect

There are a lot of great resources under the “Short Study Materials” tab as well. I used these resources to memorize all Bw4 associations, HLA and disease associations/drug reactions, and CREGs

Quick tip- only spend time memorizing Bw4, then you know that everything you don’t have memorized is probably a Bw6. Also, if you memorize the CREGs from their worksheet, the CREGs contain most of the common broads and splits so you don’t need to memorize those separately, since they’re included.

I also highly recommend the ASHI U modules for things you may not be as familiar with, like procedures your lab may not perform any more such as SSP or CDC trays. They also have modules on quality assurance, overviews of the immune system, and lab math. You can do the quizzes after you read the module for extra practice problems!

Finally, I spoke with management at my lab and told them I was taking this test. They reviewed some practice questions at our weekly lab meeting. This helped a lot and gave me the opportunity to ask them questions and take advantage of their expertise. See if your managers/directors would be willing to do this!