I have cloned my lipase gene from rice in pET-28(+) His-tag vector. Was wondering how do I choose/design the primary and secondary antibodies for western blot. I am totally new to this. Was hoping someone can help. Thanks
You can check a specific antibody for the rice lipase if available in the market. It makes job easy choose antibody raised in say rabbit or mice. Use the anti rabbit or mouse secondary HRP conjugated antibody for the western blot and you can reveal it with chemiluminiscenece. If this antibody is not available you can raise on by immunizing mice, rat or rabbit as per your requirement ( very good immunizastion protocols available on net) Good luck !!
Choosing a good primary antibody can be somewhat of a chore....BioCompare (http://www.biocompare.com/) is a good start if what you're looking for is commercially available. Your application, clonality, matching species, epitopes and crossreactivity will provide some fine tuning if there's more options. If your ab is not commercially available, then I'd go looking through literature if any researchers are using a suitable antibody + try and "borrow" some. If that fails, you may have to get it made, which is expensive, time consuming and not necessarily successful....
The way we do our western blots for antiHis-tag detection is as follows:
We use a primary antibody that binds to 6His-tags and a secondary antibody that binds to the primary antibody for signal boosting.
The primary antibodies bind to the tags (several antibodies to each single tag)and the secondary antibodies bind to the primary antibodies (several secondary antibodies to each single primary antibody), so you can see how the signal from a single His-tag can be amplified since by the end of it there will be many secondary antibodies linked to each single His-tag.
The secondary antibodies we use are horseradish peroxidase conjugated, so we can detect them on the western blot by adding ECL Western Blotting Substrate, which is a highly sensitive non-radioactive, enhanced luminol-based chemoluminescent substrate for horseradish peroxidase detection. It consists of two liquids, which you mix and then pipette on top of the western blot membrane and after a few minutes you take the membrane and expose it to photographic film in a dark room. If there are any His-tagged proteins on your membrane, then the liquid will react with the peroxidase linked to the secondary antibodies, which are bound to the primary antibodies, which are bound to the His-tags and this will emit a faint luminescence that will be clearly visible on the exposed photographic film. you will have to try several exposure times to get rid of any background luminescence, but generally a second or two of exposure is all you need for a good western blot.
The combination of animal names of your antibodies is important. Your primary antibody can come from any animal you like (we use polyclonal mouse antiHis-tag antibodies, which means they were raised in mice but detect His-tags). The secondary antibody can also come from any animal you want BUT must be able to detect the animal source of your primary antibody (we use polyclonal goat antimouse antibodies, which means they were raised in goats but detect antibodies made by mice, such as our primary antibodies).