How to deal with tissue or cells samples for ELISA assay?

Normally, the amount and ratio of each reagent a fully automated microplate ELISA analyzer needs are not the same as in our kit, so it's not applicable. 

• Whereas if you can tell cell lysates: for adherent cells, gently wash the cells with moderate amount of pre-cooled PBS and dissociate the cells by trypsin. 
• Collect the cell suspension into the centrifugal tube and centrifuge for 5 minutes at 1000×g. 
• Discard the medium and wash the cells for 3 times with pre-cooled PBS. For each 1x106 cells, add 150-250uL of pre-cooled PBS (0.01M, pH=7.4) to keep the cells resuspended. 
• Repeat the freeze-thaw process for several times until the cells are lysed fully. 
• Centrifuge for 10minutes at 1500×g at 2 - 8℃. 
• Remove the cell fragments, collect the supernatant to carry out the assay. 
• Avoid repeated freeze-thaw cycle.

Cell culture supernatant: collect samples and centrifuge for 20 minutes at 1000×g at 2 - 8℃. Collect the supernatant to carry out the assay.

Tissue homogenates: generally, mince the tissues to small pieces and rinse them in ice-cold PBS (0.01M, pH=7.4) to remove excess blood thoroughly. 

• Tissue pieces should be weighed and then homogenized in PBS (tissue weight (g): PBS volume (mL) =1:9) with a glass homogenizer on ice. 
• To further break the cells, you can sonicate the suspension with an ultrasonic cell disrupter or subject it to freeze-thaw cycles. 
• The homogenates are then centrifuged for 5 minutes at 5000×g at 2 - 8℃, collect the supernatant to carry out the assay.