The objective of the study is to collect and process urine samples from Intensive Care Unit (ICU) subjects with moderate to severe (Stage 2 or 3) acute kidney injury (AKI) for use in assessing the effects of urine sample freezing and various storage conditions on NEPHROCLEAR™ CCL14 Test results. This study is observational and will have no impact on the medical management of the subject.

Inclusion Criteria:

1. Males and females 21 years of age or older;
2. Receiving care in an intensive care unit;
3. Expected to remain in the ICU for at least 48 hours after enrollment;
4. Use of indwelling urinary catheter as standard care at the time of enrollment;
5. Subject must have acute kidney injury (KDIGO Stage 2 or Stage 3) at the time of sample collection;
6. Urine sample must be collected within 36 hours of meeting KDIGO Stage 2 criteria;
7. Written informed consent provided by patient or legally authorized representative (LAR).

Exclusion Criteria:

1. Prior kidney transplantation;
2. Comfort-measures-only status;
3. Already receiving dialysis (either acute or chronic) or in imminent need of dialysis at the time of enrollment;
4. Known infection with human immunodeficiency virus (HIV) or active hepatitis (acute or chronic);
5. Special populations, pregnant women, prisoners or institutionalized individuals.

Adult ICU patients with KDIGO stage 2 or 3 AKI.