Clearing blood for bacterial/fungal detection

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PJ
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Clearing blood for bacterial/fungal detection

 I'm working on an optical method for detection of low levels of fungal infection in human blood.  It would make things easier if I could render the blood relatively transparent (even if I have to dilute it somewhat).  I've tried lysing the red blood with distilled water, which lyses red blood cells and has little effect on fungal cells, but doesn't really clear the blood all that much.  I'm assuming that the hemoglobin is now in solution and still leaves the blood sample relatively opaque.  Any suggestions?

heehawmcduff
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You could maybe try Dextran

You could maybe try Dextran sedimentation of the red blood cells which would leave platelet rich plasma (PRP) with which you could run fungal cultures
 

Ivan Delgado
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Hi PJ,
From what you state it sounds like you are only looking at infection within red blood cells. Would it be possible that you can look for infection in plasma? I am sure you already know this, but spinning your blood (500 xg) would get rid of the cells and leave you with a pretty clear (yellowish) plasma to look at. 
If you have to look at cells, then I am not sure how you can get around the red color of RBCs.

PJ
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Ivan wrote:

Ivan wrote:

 
Hi PJ,
From what you state it sounds like you are only looking at infection within red blood cells. Would it be possible that you can look for infection in plasma? I am sure you already know this, but spinning your blood (500 xg) would get rid of the cells and leave you with a pretty clear (yellowish) plasma to look at. 
If you have to look at cells, then I am not sure how you can get around the red color of RBCs.

 Hi Ivan,  I'm looking for fungal cells in the plasma.  They won't spin down with the RBCs?

Ivan Delgado
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I do not think so. Blood

I do not think so. Blood cells will pellet at around 500 xg, while fungal cells (like bacteria) require a stronger centrifugal force to pellet. I would of course test it first (spike clean blood with a known amount of fungal cells and determine if any fungal cells come down when blood cells are coming down). I think it may be as easy as that. Of course this assumes that the fungal cells are not attached to blood cells, which is a possibility.
 
PJ wrote:

Hi Ivan,  I'm looking for fungal cells in the plasma.  They won't spin down with the RBCs?