iBlot Dry Blotting System From Invitrogen

Transferring protein can be a time consuming and somewhat messy process. The new iBlot® from Invitrogen takes care of both these issues by providing an efficient method of dry protein transfer. The new system utilizes transfer stacks that have everything in them to perform protein transfer. These include the buffers, membrane (nitrocellulose or PVDF) and the electrodes. These stacks are relatively inexpensive and come in two sizes. The standard size can transfer two mini gels at a time but for those rare occasions when only one gel is run, we use the mini stack format to reduce waste.

The machine is relatively easy to set up and runs quickly and efficiently. We found that most proteins transfer onto nitrocellulose in the recommended seven minutes. But for larger proteins (180 kd) we noticed that increasing transfer time to eight and a half minutes improved efficiency; however, the extended transfer time may result in partial loss of proteins in the 20-30 kd range. The fact that the only variable that one can change on the machine is the time of transfer greatly simplifies the troubleshooting and protocol optimization when using the iBlot.

The transfer stacks are also very easy to use. Each component is clearly labeled and organized in the box. Everything that is needed is provided, including precut filter paper and transfer membrane. There is one issue, however, none of the components are reusable. So even though the use of external buffers is eliminated, transferring proteins still produces a moderate amount of waste.

Also, sometimes, the connection between the cathode and anode is not perfect. This results in the system shutting down and a rather loud alarm sounding. This situation can usually be remedied y opening the lid and shifting the stack in order to get better alignment. The alarm on this machine is quite annoying. It sounds whenever there is an error during the run and when the run is finished. It is nice that the iBlot announces the completion of a transfer, but since it shuts down on its own, I fail to see the reason for the persistent shrill notification.

One of the best features of the iBlot is its footprint. It is not much larger then a midsized horizontal gel chamber. It has its own power supply so the only wire that is needed is from it to the socket. All in all, the iBlot is a great way to optimize protein work. The iBlot itself is inexpensive and the transfer stacks are moderately priced. Since they can be kept at room temperature and have a relatively long shelf life, they are easy to stock up on. It is a great addition to any lab that does protein work, no matter how strapped for bench space.