When you want to save a Serology record for your worker, you can do this in the Immunisation module of that worker's profile.
Search for the Serology in the Immunisation Type drop down. Enter the Result (Positive/Negative) and Status (Valid/Medical Contraindication/Declined). From our example, we have selected Hepatitis B Serology, Negative as a result and valid as status.
Enter other details as much as possible. Then click save.