Greetings, We use the Ortho Confidence system to QC our wet reagents. I have been alerted that there will be a delay in the next lot number shipment due to the (US) government shutdown. The current lot that we are using expires 10/29/2013 and the new lot # is set to ship on 10/30/2013. My question is, can I use patient samples that have established values for QC testing for the couple of days that I am without unexpired QC material? If so, how many examples of a particular value do I have to have in order for it to be a valid QC evaluation? For instance, if I want to use a group A patient to QC the anti-A reagent, how many times does that patients blood group have to have been tested? Thanks for the input.