Related Experiment Video
Updated: Jun 25, 2026

Measuring the 50% Haemolytic Complement CH50 Activity of Serum
Published on: March 29, 2010
Haemolysis index conundrum in a COVID-19 patient
Chong Qin Michael Zhao1, Jordan Steinberg2, Dennise Otero Espinal3
1Pathology and Laboratory Medicine, Northwell Health North Shore University Hospital, Manhasset, New York, USA.
None:
In this study, we report a preanalytical challenge noted in our laboratory on plasma samples from a critically ill COVID-19 patient treated with hydroxychloroquine. This is significant because, in critically ill COVID-19 patients on hydroxychloroquine, plasma samples can have a high measured haemolysis index in the absence of haemolysis, with the impact on reporting the results for potassium and other analytes.
Related Concept Videos
Blood Transfusion
Blood Transfusion Overview
A blood transfusion is a medical procedure used to replace blood lost due to injury, surgery, or to treat conditions such as anemia or cancer. During a transfusion, donor blood is...
Blood Studies for Cardiovascular System I: Cardiac Biomarkers
The essential diagnostic tools for detecting myocardial necrosis and monitoring individuals suspected of having acute coronary syndrome (ACS) include:
Troponins
Troponins, particularly cardiac troponins I and T, are the most precise and sensitive markers of myocardial injury. They are detectable within 4-6 hours of myocardial injury and remain...

