Echo user since 2008. I see these sporadicaly mainly in Obstetric patients and septic patients. My ARC reference lab advised me when we first got the machine to perform a tube screen. If that was negative, there was no point in them working ( or attempting ) to work it up. So...we do a tube screen and IF its negative, which it almost always is, we call it negative BUT put in an internal comment to perform AHG XM if needed just to be safe. I always, also, run a Ready ID just in case there's multiple allos, which has happened on occasion. I have used Gel, tube, and Solid Phase & in my opinion is detects E & JkA with way more sensitivity, like previous responses have said.