| MALD | M-Protein Isotype, Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry, Serum Mayo Clinic Laboratories in Rochester | 
      
        | MA2ES | Ma2 Antibody by ELISA, Serum Mayo Clinic Laboratories in Rochester | 
      
        | MA2EC | Ma2 Antibody, ELISA, Spinal Fluid Mayo Clinic Laboratories in Rochester | 
      
        | MACNT | Macadamia Nut, IgE, Serum Mayo Clinic Laboratories in Rochester | 
      
        | MACK | Mackerel, IgE, Serum Mayo Clinic Laboratories in Rochester | 
      
        | GNMTC | Macro/Microthrombocytopenia Gene Panel, Next-Generation Sequencing, Varies Mayo Clinic Laboratories in Rochester | 
      
        | Magnesium | Magnesium Chemistry | 
      
        | MG_F | Magnesium, Feces Mayo Clinic Laboratories in Rochester | 
      
        | FMME | Mahi Mahi IgE Eurofins Viracor | 
      
        | MALI | MAL Immunostain, Technical Component Only Mayo Clinic Laboratories in Rochester | 
      
        | MALP | Malabsorption Evaluation Panel, Feces Mayo Clinic Laboratories in Rochester | 
      
        | MCMF | Malignant Cells Cyto/Heme (Bill Only) Mayo Clinic Laboratories in Rochester | 
      
        | MGB | Mammaglobin (MGB) Immunostain, Technical Component Only Mayo Clinic Laboratories in Rochester | 
      
        | MNU | Manganese, 24 Hour, Urine Mayo Clinic Laboratories in Rochester | 
      
        | MNS | Manganese, Serum Mayo Clinic Laboratories in Rochester | 
      
        | MNRCU | Manganese/Creatinine Ratio, Random, Urine Mayo Clinic Laboratories in Rochester | 
      
        | MNCU | Manganese/Creatinine Ratio, Urine Mayo Clinic Laboratories in Rochester | 
      
        | MANGO | Mango, IgE, Serum Mayo Clinic Laboratories in Rochester | 
      
        | MBLF | Mannan Binding Lectin Complement Pathway, Functional, Serum Mayo Clinic Laboratories in Rochester | 
      
        | MBL | Mannose-Binding Lectin, Serum Mayo Clinic Laboratories in Rochester | 
      
        | Manual Differential | Manual Differential Hematology | 
      
        | FMPRE | Maple Red (Acer rubrum) IgE Eurofins Viracor | 
      
        | MSUDP | Maple Syrup Urine Disease Gene Panel, Varies Mayo Clinic Laboratories in Rochester | 
      
        | MFRGG | Marfan, Loeys-Dietz, and Aortopathy Gene Panel, Varies Mayo Clinic Laboratories in Rochester | 
      
        | MSPTC | Mass Spectrometry (Bill Only) Mayo Clinic Laboratories in Rochester |