RT Journal Article SR Electronic T1 Estimation of Serum Hyaluronidase Activity Overcoming the Turbidity Interference JF American Society for Clinical Laboratory Science JO Clin Lab Sci FD American Society of Chemistry and Laboratory Science SP 172 OP 177 DO 10.29074/ascls.24.3.172 VO 24 IS 3 A1 Nagaraju, Shivaiah A1 Girish, K Subbaiah A1 Pan, Yi A1 Easely, Kirk A A1 Kemparaju, Kempaiah YR 2011 UL http://hwmaint.clsjournal.ascls.org/content/24/3/172.abstract AB The assay of mammalian hyaluronidases (HAases) is important in understanding the role of the hyaluronan-hyaluronidase (HA-HAase) system in various pathophysiological processes. Despite several quantitative assay method options, the Morgan-Elson colorimetric method modified by Reissig et al [1] is considered the best for determining the activity in clinical samples. However, the sensitivity of the method was greatly limited by presence of protein above 400 μg due to turbidity interference that led to chromogen quenching. Therefore, an effort has been made to reinvestigate the Reissig et al method. In the re-investigated method, a standardized optimal 0.32 M potassium tetraborate (PTB) was used against 0.13 M (native) to overcome the turbidity interference. The estimated mean OD at 585 nm of serum for native method was 0.043 (95% CI: 0.040 to 0.045), while that for the re-investigated method was 0.138 (95% CI: 0.133 to 0.143, p<0.0001). The mean OD at 585 nm of serum of native method was significantly lower than that of re-investigated method (p<0.05) at all protein levels. This was also true for estimated mean OD at 585 nm of plasma. The mean intrasample CVs for native and re-investigated methods were 0.9% and 0.5%, respectively, for normal serum. Furthermore, the repeatability coefficient of normal serum for native was 0.003 IU, while re-investigated method experienced that of 0.002 IU.