Bilirubin, Amniotic Fluid Scan
| Bilirubin, Amniotic Fluid Scan | | | |
| Number | | 002196 |
| CPT | | 82143 |
| Synonyms | | Amniotic Fluid Bilirubin ; Delta OD, Amniotic Scan ; Liley Scan ; OD 450 |
| Test Includes | | Delta OD value at 450 nm |
| Special Instructions | | The request form must include weeks of gestation. |
| Specimen | | Amniotic fluid, protected from light |
| Volume | | 5 mL |
| Minimum Volume | | 2 mL |
| Container | | Amber plastic transport tube with amber stopper. (If amber tubes are unavailable, cover standard transport tube completely, top and bottom, with aluminum foil. Identify specimen with patient name directly on the container and on the outside of the aluminum foil. Secure with tape.) For amber plastic transport tube and amber stopper, order LabCorp No 23598. |
| Collection | | Protect specimen from light. Amniocentesis is performed by physician. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested. |
| Storage Instructions | | Protect specimen from exposure to light since bilirubin is unstable in light. Although sterile specimens kept in the dark are reported to be stable for 9 months refrigerated and at least 30 days at room temperature, it is probably wiser to keep the sample frozen until it can be analyzed since it cannot be easily replaced if instability is suspected to have affected the result. |
| Causes for Rejection | | Excessive exposure to light; grossly bloody specimen; specimen contaminated with meconium (A single passage into the amniotic fluid will require about 3 weeks to clear.) |
| Reference Interval | | Varies with gestational age |
| Use | | Evaluate cases of suspected maternal-fetal blood incompatibility, hemolytic disease of the newborn |
| Limitations | | No correction for meconium contamination possible |
| Methodology | | Spectrophotometry |
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