Thank you for your time. I separated red blood cells from a whole blood sample purchased from a blood bank. In isotonic solution, the red cells appear crenate. I would like to know if there is anything wrong with my procedure. I used the following controls:
I purchased two samples which came from two different donors. Both samples are more than 48 hours old.
I used three different solutions to spin the blood including RMPI 1640, saline solution, and phosphate buffered saline. I used multiple solutions because the RMPI is past the expiration date.
I spun one sample at high speed and the other sample at low speed.
The first sample was delivered at room temperature, it was not on ice. The second sample was on ice. I believe the buffers and the blood sample were roughly the same temperature when I spun them.
I mixed the buffer solution with the RBCs by gently rocking the test tubes back and forth.
Thinking that the problem may be when I preparing slides, I cut the tip of the pipette in case pressure was disturbing them.
I used both refrigerator and room temperature isotonic solution when preparing the slides.
I use a spacer in the slides with double sided tape and I seal it with nail polish. I'm not sure if that should matter.
If you have any ideas as to why the RBCs look like burr cells in isotonic solution, I'd greatly appreciate it if you'd share them with me. Thank you!