Settings of centrifuge to separate blood samples

[Brenda K Hutson]

Eric,

Coinicidentally, I was looking online at centrifuges because we need to purchase a new one. I came across a statement while looking at the size of EDTA tubes (because 1 Manufacturer asked that question), and came across this sentence:

All non-gel blood collection tubes, including those that contain heparin, EDTA and non-gel serum tubes can be centrifuged at ≤1300 RCF for 10 minutes.

Interesting.....

Brenda Hutson

[eric1980]

Hi, Brenda.

Back then, I was concerned that the spinning time is overly long and could be shortened at a higher speed to achieve platelet-poor plasma. Did the manufacturer also provide any guidelines on how the speed could be if the customer would like to shorten the spinning time?

[Brenda K Hutson]

No, I looked for that but did not see it. Also of interest....our centrifuge died and we are ordering a new one; but until then, we are using the one in Coag. It spends at 3,000 RPMs for 10 mins. And I am not going to question it; but I am going to buy one that won't take that long....:tongue:

Brenda

Hi, Brenda.

Back then, I was concerned that the spinning time is overly long and could be shortened at a higher speed to achieve platelet-poor plasma. Did the manufacturer also provide any guidelines on how the speed could be if the customer would like to shorten the spinning time?

[SMILLER]

I really do understand the importance of standardisation and the reasons why there are SOPs in place. But in my personal (which, in Malcom Needs' words, I am prepared to be rebutted) opinion, using my lab's settings will only cause more stress to me when work is becoming overwhelming, increasing the chances of me making mistakes by clouding my judgement, which is critical in organisation of work and priortisation of processes. This is why I chose to use my own judgement to to change the setting to make sure that I could work my best.

Anyway, what frustrates me is that the SOP (centrifugation settings in this case) do not have any basis, as my seniors could only refer generally to the AABB TM but could not produce the information to me. What further proves to me that this setting is seriously flawed and have no basis is the fact that we changed both of our centrifuges a few months ago, we used exactly the same settings (3000rpm x 10mins) over to the new centrifuges which have a much shorter rotor!

Eric, just two observations here. One, we all can appreciate the hassle of putting up with SOPs that seem to interfere with doing our work efficiently, but y ou simply cannot ignore policies and procedures when working in the health field because you are "stressed" at times. If something comes up that has a direct and immedaite impact on patient care, you would, of course, have an obligation to take care of it--but through the proper channels. This would include doing whatever research you need to support your point of view. There have been some good suggestions here on how to do that regarding this rather minor centrifuge time issue.

And B, if you changed your centrifuges to new ones with shorter rotors, it means that the G force is less. It seems like you would need to increase the spin time and/or speed, NOT decrease it to get the same effect with the new fuges.

Just my two cents, good luck, Scott

- - - Updated - - -

I really do understand the importance of standardisation and the reasons why there are SOPs in place. But in my personal (which, in Malcom Needs' words, I am prepared to be rebutted) opinion, using my lab's settings will only cause more stress to me when work is becoming overwhelming, increasing the chances of me making mistakes by clouding my judgement, which is critical in organisation of work and priortisation of processes. This is why I chose to use my own judgement to to change the setting to make sure that I could work my best.

Anyway, what frustrates me is that the SOP (centrifugation settings in this case) do not have any basis, as my seniors could only refer generally to the AABB TM but could not produce the information to me. What further proves to me that this setting is seriously flawed and have no basis is the fact that we changed both of our centrifuges a few months ago, we used exactly the same settings (3000rpm x 10mins) over to the new centrifuges which have a much shorter rotor!

Eric, just two observations here. One, we all can appreciate the hassle of putting up with SOPs that seem to interfere with doing our work efficiently, but y ou simply cannot ignore policies and procedures when working in the health field because you are "stressed" at times. If something comes up that has a direct and immedaite impact on patient care, you would, of course, have an obligation to take care of it--but through the proper channels. This would include doing whatever research you need to support your point of view. There have been some good suggestions here on how to do that regarding this rather minor centrifuge time issue.

And B, if you changed your centrifuges to new ones with shorter rotors, it means that the G force is less. It seems like you would need to increase the spin time and/or speed, NOT decrease it to get the same effect with the new fuges.

Just my two cents, good luck, Scott

[SMILLER]

I really do understand the importance of standardisation and the reasons why there are SOPs in place. But in my personal (which, in Malcom Needs' words, I am prepared to be rebutted) opinion, using my lab's settings will only cause more stress to me when work is becoming overwhelming, increasing the chances of me making mistakes by clouding my judgement, which is critical in organisation of work and priortisation of processes. This is why I chose to use my own judgement to to change the setting to make sure that I could work my best.

Anyway, what frustrates me is that the SOP (centrifugation settings in this case) do not have any basis, as my seniors could only refer generally to the AABB TM but could not produce the information to me. What further proves to me that this setting is seriously flawed and have no basis is the fact that we changed both of our centrifuges a few months ago, we used exactly the same settings (3000rpm x 10mins) over to the new centrifuges which have a much shorter rotor!

Eric, just two observations here. One, we all can appreciate the hassle of putting up with SOPs that seem to interfere with doing our work efficiently, but y ou simply cannot ignore policies and procedures when working in the health field because you are "stressed" at times. If something comes up that has a direct and immedaite impact on patient care, you would, of course, have an obligation to take care of it--but through the proper channels. This would include doing whatever research you need to support your point of view. There have been some good suggestions here on how to do that regarding this rather minor centrifuge time issue.

And B, if you changed your centrifuges to new ones with shorter rotors, it means that the G force is less. It seems like you would need to increase the spin time and/or speed, NOT decrease it to get the same effect with the new fuges.

Just my two cents, good luck, Scott

[eric1980]

Brenda, in coag, I'm using Statspin, which is a small centrifuge, that spins for 3mins at ?g. Running the plasma under our FBC analyser, I can get between 2-7x10^9/L which I think is very efficient considering the time we spin, and the result we get. For a high workload blood bank, this could be a godsend. It's just that the centrifuge seems filmsy and is very sensitive to balance...

And I would avoid using rpm as much as possible unless I'm talking about cars. Personally I dismiss this unit as it do not mean anything considering the various length of rotors in the market.

Scott, I understand what you mean. Thanks. I believe I made the right choice by moving on.