Experimental Analysis of Liquid Photo Stable Bilirubin From Pooled Human Serum and Its Usage as Endogenous Bilirubin Control Material in a Clinical Laboratory

Introduction: Quality control is an integral part of any clinical laboratory, which requires constant maintenance to deliver robust, reliable reports. Bilirubin in control material is an extremely photosensitive and unstable material; thus, we aimed to prepare endogenous bilirubin control material from pooled human serum and benchmark its stability against commercially available control materials at a xed temperature range of 2°-8°C. Material & Methods: Endogenous bilirubin control material was prepared from the pooling of residual serum samples, where each total bilirubin level (Diazo method) was in the ≥3.0 mg/dl to ≤10.0 mg/dl range. Samples that were positive for HIV I/II, HbsAg, anti- HCV, Haemolyzed, Lipemic, SGOT, and SGPT >250U/L, Insufcient samples (<100 µL) were excluded. The baseline mean was established. Remnant serum was separated equally into a falcon tube and an amber vial shielded with aluminium zip-lock pouch, containing a silica gel packet enclosure. (A/AL). Commercial controls were reconstituted, and baseline means were settled. All control sets were stored at 2-8°C properly. Total bilirubin was measured daily from each control set for thirty days. A comparison of means, standard deviation, and CV% was done with ANOVA and post hoc Tukey HSD; a p value (< 0.05) was considered statistically signicant. Results: Established baseline mean, nal mean ±standard deviation (mg/dl), and CV% for total. bilirubin (mg/dl) from Falcon tube (8.0, 3.88±1.94,3.79), A/AL (8.0, 7.32±0.51,0.26), ERBA PATH (4.55, 3.21±1.10,1.22), RANDOX LEVEL 3 (5.43, 3.54±1.66,2.77), and TERSACO (4.64, 2.98±1.47,2.16) were observed, respectively. Statistically signicant differences were recorded from the baseline means on the contrary to the nal means of Falcon Tube, ERBA PATH, RANDOX LEVEL 3, and TERSACO (p <0.001), but there was no statistical difference between the baseline mean and nal mean of A/AL (p 0.226). Conclusion: Our study concludes that endogenous bilirubin control material prepared from pooled human sera showed effective stability for thirty days at 2°-8°C when kept in an amber vial shielded within aluminium zip-lock enclosing a silica gel packet and can be used as in-house bilirubin control material. However, rapid deterioration was observed when stored in a falcon tube. Other commercial quality control materials showed acceptable analytical performance for 12-14 days.