I agree with all the posters here who ask you to return to SOP until you have convinced your superiors and they have changed the SOP. Here is how I switched from a 10 minute spin to a 2 minute spin (I am a supervisor):
For each of 20 specimens (10 w a pos antibody screen, 10 with a negative antibody screen) I spun according to the SOP (10 min) and on a worksheet I commented as to the visual appearance, including clarity, hemolysis, and the sharpness of the interface between cells and plasma. Then I tested the specimens according to SOP and reported. Then, I completely resuspended the specimens on a tube rocker and respun them at the new setting (StatSpin3) for 2 min. After the spin I again recorded the visual apearance and then repeated all the testing and recorded the results on a worksheet (did not report). I then compared the apearance and results. There was no difference in any of the visuals or results, so I considered the new process to be valid. I wrote up the mini-study and sent it to my Medical Director for approval to change the SOP accordingly. Once approved, I began making the SOP changes. Then, staff read the new SOP, were trained on the new centrifuge settings, demonstrated competency. Then I announced to all staff that we would 'go live' with the new settings on a certain date. I realize your lab did not perform a comparison of any kind when they got their new centrifuge, but they should have. If you cannot find a way to convince them, I am sorry for you, but you MUST continue to follow SOP as written, or speak with your Medical Director (physician in charge of the lab) about your scientific concerns so that a proper change may occur. Best of luck.