Many teaching/training laboratories do not have access to a source of specimens that will give a full range of serologic reaction grades, or those representative of ABO weak subgroups. As a consequence many laboratory staff may lack a learning opportunity or continued experience in detecting weak serologic reactions. The ability to manually score serologic reactions is important particularly as part of disaster response planning, as laboratories may need to be relocated to areas without support of automated machines. In such situations staff need to be both competent and confident in their ability to manually perform serology. Group O RBCs can be controllably modified (koded) with blood group A and/or B Function-Spacer-Lipid (FSL) constructs to mimic the full serological range of weak ABO subgroups. These so-called kodecytes (KODE™ construct modified cells) already have a range of uses including quality control systems and will react with most monoclonal anti-A and B blood grouping reagents. The quality (sensitivity and specificity) of various monoclonal reagents varies significantly. This FSL-A+B(tri) Serologic Teaching Kit has been specifically designed for teaching purposes to create red cells (kodecytes) expressing reproducible and controlled levels of blood group A and B antigens to group O red cells. The aim is create kodecytes that can determine and improve the skill level of the operator to detect weak serologic agglutination reactions that may be encountered when blood typing weak phenotypes of blood group A or B. FSL-A+B(tri) Serologic Teaching Kit is a mixture of KODE™ technology FSL blood group A and B trisaccharide constructs designed for teaching/training purposes. This product contains a mixture of 0.5 mg of FSL-A(tri) and 1.5 mg of FSL-B(tri). All FSL constructs disperse in saline solutions and spontaneously and stably incorporate into cell membranes.