Technically, no. A BLOB is a BINARY Large Object. Blobs are usually not used to store text, thus it really doesn't make sense to do a text search on a blob. Of course, there could be text embedded in the blob, such as track data in an mp3. But still, I doubt any database supports text searching in a binary large object. To do this, you will probably need to stream the binary data and search it yourself. The other kind of LOB is a CLOB, character large object. Whether or not you can do a text search on a CLOB will be database dependent. I know Oracle 9i supports some string functions for CLOB data. You will need to check your specific database to see if you can do text search on a CLOB.
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com