Table 3.
Results of Environmental Assessments
| Tested object | Tested area | Bluestar Forensic test | Hexagon OBTI test | Interpretation |
|---|---|---|---|---|
| Dialysis machine 1 | ||||
| Screen | No reaction | … | … | |
| Keyboard | Reaction | Negative | Cross-reaction with remnant bleach or extremely low concentration of blood | |
| Acid and base administration port | No reaction | … | … | |
| Machine’s right side | Not tested | … | Visible bloodstains near blood pressure holder | |
| Artery blood pressure cuff | Reaction | Negative | Cross-reaction with remnant bleach or extremely low concentration of blood | |
| Prime bucket | Reaction | Negative | Cross-reaction with remnant bleach or extremely low concentration of blood | |
| Dialysis machine 2 | ||||
| Screen | No reaction | … | … | |
| Keyboard | No reaction | … | … | |
| Acid and base administration port | Reaction | Negative | Cross-reaction with remnant bleach or extremely low concentration of blood | |
| Machine’s right side | Reaction | Negative | Cross-reaction with remnant bleach or extremely low concentration of blood | |
| Blood pressure cuff | No reaction | … | … | |
| Prime bucket | No reaction | … | … | |
| Dialysis chair | ||||
| Headrest | No reaction | … | … | |
| Armrest | No reaction | … | … | |
| Footrest | No reaction | … | … | |
| Chair side | No reaction | … | … | |
| Side table | Reaction | Positive | Invisible bloodstain | |
| Two chairs in waiting area | ||||
| Seat surface | Reaction (1 chair) | Positive | Invisible bloodstain | |
| Bathroom | ||||
| Sink | Reaction | Negative | Cross-reaction with remnant bleach or extremely low concentration of blood | |
| Door handle | No reaction | … | … | |
| Light switch | No reaction | … | … | |
| Toilet handle | No reaction | … | … | |
| 4 television sets within dialysis stations | ||||
| 4 sets with visible stains (of 24 sets) | Not tested | Positive (1 stain tested) | Visible bloodstain | |
| Biohazard trash can with visible blood stain | ||||
| Opening area of can | Strong reaction | Positive | Served as positive control | |
NOTE. Bluestar Forensic is a forensic chemiluminescent agent that reacts with hemoglobin; Hexagon OBTI is an immune assay used to confirm the presence of human hemoglobin.