I am seperating my proteins using microcentrifuge(Max.volume 1.5ml). I wonder what volume of sample should actually be put at maximum. because I remember someone saying that it should be two third of the max. volume, which is 1ml in this case. But now I need to centrifuge 1.5ml of my sample and want to know if its OK.
I want to avoid to seperate it into 2X0.75ml if possible due to the amount of work. There are no other type of centrifuges or rotors are currently available in this lab. And also, if anyone can explain why we should not centrifuge using max. volume( if this statement is true)? Sorry if this question is too basic. I am looking forward to hearing from you.
2006-08-30 01:15:17 · 3 answers · asked by mineminezou 1 in Science & Mathematics ➔ Biology
From experience, you should not fill microfuges to the top. You will not 1. be able to spin down all your protein - some of it will stick to the side 2. be able to decant the liquid without disturbing and losing some of your protein in the liquid.
I am sure that there is a scientific explanation for this but I do not know what it is ... probably something to do with the force exerted and the length of path the protein until it encounters the side walls. Remember that the microfuge is slanted and your protein solution will be also be slanted in the fuge.
If you look at the protein pellent even in a small volume after centrifuging there is a bit of a smear (depending upon amount of protein).
If you do not want to use a lot of tubes, put small amount of the solution in one tube, balance with a tube of water. Discard liquid from protein tube, add more solution, centrifuge again. That way your protein will be in one tube but you will have centrifuged a few times.
2006-08-30 02:24:19 · answer #1 · answered by random.acts 3 · 0⤊ 0⤋
Not sure as to your time frame for your work, but if you are using eppendorf microcentrifuge tubes, (1.5 ml) in a standard microfuge (18 tube capacity), you can use different tubes. QIAGEN has 2 ml tubes that they use in some of their kits. Also, Sarstedt has 2 ml tubes available. Either way, you will still have some "head space" in your tubes and be able to use 1 tube per sample.
2006-08-31 22:09:14 · answer #2 · answered by opus902 2 · 0⤊ 0⤋
How many samples do you have and you can't do 2x0.75ml?
Are you using a kit?
Volumes depend on your exact set-up and kit you're using.
2006-08-30 08:23:26 · answer #3 · answered by bellerophon 6 · 0⤊ 0⤋