Final answer:
Grey tubes commonly contain sodium fluoride as an anticoagulant and are used for glucose tests, sent to the chemistry lab section for analysis. Blood agglutination with both anti-A and anti-B antibodies indicates an AB blood type, which is a normal response for this blood group.
Step-by-step explanation:
When collecting a blood sample in a GREY tube, the test typically run is a glucose test, such as fasting blood sugar, glucose tolerance test, or lactic acid measurement. The anticoagulant used in grey tubes is typically sodium fluoride and sometimes also potassium oxalate. The primary purpose of these additives is to preserve glucose levels and prevent the blood from clotting. The lab section that these samples are typically sent to is the chemistry section for analysis.
Regarding the question about the blood type testing: If both samples visibly agglutinate after the addition of anti-A and anti-B antibodies, this result indicates that the patient's blood type is AB. This agglutination is a normal response for someone with blood type AB, which means that they have both A and B antigens on the surface of their red blood cells. Therefore, the technician has not made an error.
In the other two examples provided, blood samples are collected into lithium heparin tubes and EDTA tubes, which are not grey but are typically used for plasma collection after centrifugation for various other tests.