A drop of blood, a Minute's wait: rapid blood typing put to the test

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Subjects will be enrolled in the Main Cohort if they meet all of criteria IC.1 through IC.6. Subjects will be enrolled in the Rare-Phenotype Cohort if they meet all of criteria IC.1 through IC.7: 1. Subject is 18 years of age or older at the time of enrollment. 2. Subject is able to provide written informed consent prior to any study-related procedures. 3. Operator or study staff is able to obtain required data to complete the subject's Enrollment Questionnaire. 4. Subject is able and willing to complete all required study procedures on the allocated testing day. 5. Subjects is able to speak/read/write in English or Spanish. 6. Subjects is willing to provide: * Two (2) capillary fingerstick whole blood samples, and * Venous whole blood samples collected by venipuncture (approximately 10 mL), as required for the study. And * If required, a maximum of two (2) further fingerstick whole blood samples in the case that the initial INSTI and/or TruPlex test results are invalid. Additional Inclusion Criterion for Rare-Phenotype Cohort Enrollment: 7. Subject has a previously documented rare ABO subgroup or RhD variant phenotype. Exclusion Criteria: Subjects will be excluded from the study if they meet any of the following criteria: 1. Subject has known bleeding disorder or any other medical condition that, in the opinion of the Investigator or Operator, contraindicates fingerstick or venipuncture. 2. Subject has received a blood transfusion within the past 120 days. 3. Subject is currently using therapeutic anticoagulants (e.g., warfarin, heparin, or direct oral anticoagulants \[DOACs\]) that, in the opinion of the Investigator or Operator, may interfere with sample collection or test performance. 4. Subject has any condition which, in the opinion of the Investigator or Operator, would: * Place the participant at undue risk, * Interfere with completion of study procedures, * Compromise the informed consent process, or * Bias the interpretation of study results. Examples include, but are not limited to: intoxication, acute illness, visible distress, or inability to understand study procedures.