Here is a provocative follow-up from Dr. Ning Tang describing PTT reagent sensitivity to LAC :
Hi, Prof George,
We performed an experiment to compare APTT of samples with or without LAC by different APTT reagents. The results suggest that the type of activator in APTT reagent seems not to be the determinant of sensitivity for LAC (see in attachment), I hope that's interesting for our discussion.
Attachment: /sites/default/files/book1.xls.pdf
Hello, Dr. Ning Tang, the cases you've tested seem to indicate near-equal sensitivity by silica-based and ellagic acid-based reagents, confirming the comments from Mr. McGlasson and Dr. Favaloro. Although at first glance the silica-based PTT reagents appear to have misclassified the weak LAC , in all three cases the results are borderline when compared to the upper limit of the RI.