CAP states: "There are records of acceptable reactivity and specificity of typing sera and reagent cells on each day of use, including a check against known positive and negative cells or antisera, or manufacturer's instructions for daily quality control are followed." Immucor package inserts for several reagents do not include instructions for a negative control. Do we follow what Immucor suggests or add in a negative control too? We currently test antisera against eachother for our daily QC, but are considering changing to Immucor corQC, but noticed there is no negative control for some reagents. For those of you using corQC, how do you address this? thanks!