Thursday, October 29, 2009

RNA extraction from tissues

Procedures for RNA extraction from tissues:

1. pre-weigh an empty cryovial
2. take the tissue specimen out from the cryovial and place it on a 100mm petri dish
3. use a scapel and sterican (like fork and knife) to cut the tissue into desired size
4. transfer the tissue into the pre-weigh cryovial and weigh again (this will give the exact weigh of the tissue being process)
5. transfer the surplus tissue into the original cryovial and keep in the nitrogen tank
6. add 650µl of RLT buffer into the cryovial
7. pound the tissue using a pipette tip until the solution turn orange in colour.
8. transfer the solution into QIA shredder column and centrifuge at 14 000rpm for 4minutes
9. transfer the flow through into a new eppendorf tube and add in 550µl of 70% ethanol
10. centrifuge the eppendorf tube at 14 000rpm for 3 minutes
11. transfer the solution into Rneasy column and centrifuge at 14 000rpm for 15 seconds
12. discard the flow through
13. add 700µl RW1 buffer into the Rneasy column and centrifuge at 14 000rpm for 15 seconds
14. discard the flow through
15. add 500µl RPE buffer into the Rneasy column and centrifuge at 14 000rpm for 15 seconds
16. discard the flow through
17. centrifuge the Rneasy column at 14 000rpm for 1 minute
18. transfer the Rneasy column into a new sterilised round bottom tube
19. add 30µl Rnase-free water and centrifuge at 14 000rpm for 1 minute
20. transfer the flow into the column and centrifuge at 14 000rpm for 1 minute
21. the flow through is the RNA extracted

Thing to note
- after taking the cryovial of tissue out from the nitrogen tank, keep it in liquid nitrogen.

Yeo Sok Kian Jocelyn

0703359J

7 comments:

  1. Jocelyn,

    Can you explain the purpose of the buffers ie used in this protocol? Such as the RLT buffer etc.
    Thanks.

    Li Yinliang Alex 0704894E
    TG02 Group 8
    30 October 2009

    ReplyDelete
  2. Hi

    When the tissue is stored in liquid nitrogen, are there any reagents added into the cryovial to maintain the morphology of the tissues?

    Liyana
    0703827F

    ReplyDelete
  3. Is there a certain/minimum amount of tissue to get the maximum amount of RNA needed?

    Muna 0703791D

    ReplyDelete
  4. Hi Jocelyn

    Just wonder what kind of tissue that u extract RNA from? Coz I also do RNA extraction from tissue (liver) but I need to grind it into powder, ehehhe.

    Vo Thu Hong Anh [Jess]
    0705364H

    ReplyDelete
  5. Hi Jocelyn,

    What is the purpose of the 70% ethanol? Can other grades be used?

    Yvonee
    0703189A

    ReplyDelete
  6. Hi Jocelyn,

    Sorry to ask but does Rnase free water refers to ultrapure water ?

    Stanley
    0702201E

    ReplyDelete
  7. To Alex,

    Purpose of each reagent,
    RLT buffer-to perform lysis so to release the RNA
    Ethanol-create condition that promotes selective binding of the RNA to the RNeasy membrane
    RW1 buffer-wash the membrane
    RPE buffer-wash the membrane
    RNase-free water-elute the RNA


    To Liyana
    the cryovial itself contain the freezing media.


    To Muna
    according to the RNeasy Mini handbook, the maximum amount of the starting material, in this case the tissue, should not exceed 30mg.


    To Jess
    the tumor that we handle is tumor tissue, but i do not know the site of extraction exactly.


    To Yvonee
    the ethanol is to create condition that promotes selective binding of the RNA to the RNeasy membrane. 70% ethanol work the best for mammalian cells and tissues.


    To Stanley
    yes.


    From
    Yeo Sok Kian Jocelyn
    0703359J

    ReplyDelete