###### Abstract  
An immunomodthornographic detection of myoglobin (MG) as a specific marker of porcine muscle tissue has been developed. The method is based on the sandwich lateral flow immunoassay (LFIA) with gold nanoparticles (AuNPs) as a label. The developed test system determines MG with a detection limit of 5 ng mL\({}^{-1}\) within 15 min. A specific determination of porcine MG and no cross-reactivity with MG from other tested mammals and bird species was demonstrated. The test system is able to detect pork additives, as low as 0.01% (_w/w_), in minced beef. A technique of MG extraction from muscle tissue has been proposed which allows for rapid and efficient MG extraction from meat samples (within 20 min). The developed test system can serve as an effective means of controlling the authenticity and quality of meat products.  
myoglobin; lateral flow assay; colloidal gold; porcine meat +
Footnote †: journal: Medical  
the amount of meat identified in the finished product [10]. For the quantitative determination of pork in meat products, [PERSON] et al. used a calibration curve obtained from preliminary analysis of chicken meat containing 0.1-25% (_w/w_) pork [9]. It should be noted that the combination of membrane immunomodromagnraphy with molecular genetic analysis enabled the determination of pork, as low as 0.01%, in a meat mixture, which greatly simplified the process of testing. However, even in this case, a complex and time-consuming technique of sample preparation was required before analysis [11; 12].  
Immunochemical methods, in particular the ELISA and lateral flow immunoassay (LFIA), can be used for rapid detection in a large number of samples with high sensitivity and specificity. LFIA is based on the use of a multimembrane composite with preliminary immobilized specific reagents. The analytical procedure consists of immersing the test strip into the extract obtained from the food product and assessing the result after 10-20 min [13; 14]. An important stage of the LFIA developed for assessing the quality of raw and cooked meat products is the selection of a molecular marker, which can be of a protein or peptide nature. To identify pork, troponin I [15], porcine serum albumin [16], and porcine immunoglobulins [17; 18] were used as markers.  
Myoglobin (MG) can be considered to be a relevant marker for the immunodetection of pork. This cytoplasmic hemoprotein has been expressed in skeletal muscles and cardiac myocytes and has demonstrated significant variability of amino acid sequences for different species [19; 20]. [PERSON] et al. used MG as a marker for the ELISA of beef content in meat products [21]. [PERSON] et al. developed an immunomodromagnographic test system based on two clones of anti-MG antibodies with different specificities to detect the fresh, not heat-treated, meat of cetaceans [22]. The application of MG as a marker for pork and horsemeat detection by high-performance liquid chromatography has been described by [PERSON] et al. [23] and [PERSON] et al. [24]. The obtained results confirm the efficiency of MG as a species marker for identifying the muscle tissue of different animal species. However, to our knowledge, the detection of MG for halal control using rapid immunoassay has not been described.  
In this study, for the first time, an immunohistochemical test system for the rapid determination of pork in meat products using MG as a detectable biomarker was developed.