Hi, 

Yes, and it named as Platelet Storage Lesion. Platelet activation starts from the first beginning of isolation.  it may  be reversible changes in response  to the soluble agonists such as ADP and TXA2. Further activation of platelets may lead to alpha granule release  that make them pro-inflammatory . in this step platelets express pro- inflammatory molecules such as P-selectin and CD40L. From this step platelets engage in an irreversible activation.If the inside-out signaling stimuli keep continue ,platelet may be activated further with a sustain increase in inter-cellular calcium leading to pro-coagulant activity that is manifested best by SCIP formation in which platelets get  Annexin V positive.

Thank you for your information...If so then during storage platelet activates and it goes on increasing as storage period but some point am observing activation is getting decreased..why? For example on 3rd day of storage platelet activation is 2.4 (MFI)or 23% on 5th day it increased to 3.5(MFI) or 43%. But on day 7 it becomes 2.1 (MFI) or 19% it decreases hows this possible?

Dear Malikarjun,

That is flow cytometry assay but wondering which test you talking about.

Platelet activation and progressive apoptosis takes place during apheresis and storage - above all after pathogen reduction. Platelet storage in additive solution instead of plasma induces also higher platelet activation and cytokine release.

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Dear Mehran Ghasemzadeh,

You are right I am talking about flow cytometric analysis of platelet activation. As described earlier how can platelet activation decrease during the storage. I Assume that, as storage period increase activation increase...is their any mechanism which can reverse the process during the process?