Participating in recognition of the altered structures in the invertebrate during embryogenesis, morphogenesis and the formation of the immune response,,. Cross-reactivity of MBL-AJ and human serum lectin MBL detected by the antibodies against MBL-AJ suggested the presence of common antigenic determinants. However, the MBL-AJ specificities resulted in the absence of the MBL-AJ interaction with the components of the healthy patient’s serum have been found to facilitate the detection of the slight structural differences of glycans, excluding the wrong positive results in the assayed samples. Although cancers of ovaries, cervix and uterus are regarded as ICI 182780 difficult and expensive for the detection at an early stage, the method with the use of MBL-AJ has allowed identifying statistically reliable differences between the levels of the lectin-binding CEA between healthy women and patients with cervical cancer, and between patients with benign and malignant neoplasm. Moreover, it is important that MBL-AJ-based method gives a possibility to assess tumours noninvasively. Currently, construction of the fusion or tagged proteins is a useful method to obtain chimeric molecules with an improved functionality or, moreover, dual mode of action such as enzymes with specific binding activities,,,. Here we report on genetic engineering and overexpression in E.coli of the bifunctional hybrid protein CmAP/MBL-AJ with the alkaline phosphatase CmAP of marine bacterium and the Far Eastern holothurian lectin MBL-AJ activities in the purpose of further improving the enzyme-linked lectin assay for diagnosing of cervical cancer,,. Although the holothurian MBL-AJ and mammalian lectins, including human MBL, had common properties to recognize bacterial mannans, the differences in the carbohydrate-binding specificities were found to be significant. It has been previously shown that holothurian lectin MBL-AJ interacts with the promising cancer biomarkers in the following order of the lectin-binding affinity: CEA, embryonic a-1-acid glycoprotein, trophoblast-specific b1-glycoprotein and a-fetoprotein isolated from the abortive and retroplacental blood. MBL-AJ is not inhibited by monosaccharide, which is in the content of the normal human glycoconjugate’s carbohydrate chains, and does not interact with the human blood serum components. On the base of the unique carbohydrate-binding domain that defines the MBL-AJ ability to distinguish microheterogeneity of the malignant or normal cell glycoconjugates, a novel method of cervical cancer diagnosis has been developed. The method was adapted to determine the quantitative level of the lectin-binding forms of CEA in the vaginal secretions of patients. The vaginal secretions were collected from the proximal uterine cervix surface, irrespectively on the age and physiological state of patients. The method with the use of MBL-AJ has allowed identifying statistically reliable differences between the levels of lectin-binding CEA between healthy women and patients with cervical cancer, and between patients with benign and malignant neoplasms. Moreover, it is important that MBL-AJ-based method give a possibility to assess tumours noninvasively.