Question:

Please imagine the situation that a patient’s blood sample is drawn under these scenarios:

1. The blood sample is drawn on a day too late for same day centrifugation into serum (sample kept in refrigerator) and will only be centrifuged next day, e.g. 24 hours later.

2. The blood sample is drawn on Saturday, too late for same day centrifugation and can only be kept in refrigerator and centrifuged on Monday morning. It could be about 48 to 60 hours after the blood sample is drawn under the above scenarios. Would it then be advisable for the blood sample to be stored in Z Serum Sep Clot Activator i.e. gel tube? Will this minimize risk of haemolysed serum?

Answer:

Haemolisation occurs in 90% of the cases during the blood drawing procedure. In 10% of the cases, haemolisation occurs during bad storage of the sample, when not centrifuged. Main reasons: high temperature or partial or total freezing of sample. Your scenarios 1 and 2 are applicable, only condition: The sample should never freeze! Red blood cells burst when they freeze, result: haemolisis. Some refrigerators, which have no active air and no freeze control, may freeze the sample, then haemolisis in inevitable. The tube used has no influence, as the blood is not separated from serum yet. You don’t need a clot activator when the blood is not centrifuged within an hour.

(Answer is by Dr. Camille Lieners, Scientific Advisor ImuPro)