M+S Neuropathy Panel - see Sulfatide Loading Study
Magnesium
Magnesium RBC
Malaria Smear
MALSM 
Manganese
Mantle Cell Lymphoma Panel
Marijuana Confirmation - see Cannabinoids Confirmation
Marijuana Screen - see Cannabinoids Screen
MDMA
Mebaral - see Mephobarbital
Meconium - see Drug Screen Meconium
Mephobarbital + Phenobarbital Serum
Meprobamate Level
Mercury Blood
Mercury Urine
Metabolic Quantitation Urine - see Aminio Acid Quan Urine
Metabolism Screen Urine
Metanephrines
Metanephrines Fractionated 24 hr Urine
Methadone
Methadone Urine Confirmation
Methadone Urine Screen
Methaqualone Quan Blood
Methemoglobin
Methotrexate
Methsuximide Level
Methanol
Methylenetetrahyrdofolate Reductase
Methylmalonic Acid (MMA) Quant Serum
Methylphenidate
Metyrapone Response
Mexiletine Level
Mexitil - see Mexiletine
MG - see Magnesium
MGMT Assay Panel
Microalbumin Urine Timed
Microalbumin Urine Random
Microsomal AB Liver Kidney
Microsomal AB Thyroid Peroxidase - see Thyroid Peroxidase AB
Microsporidium
Milk Allergen
Miltown - see Meprobamate
Mitochondrial AB Screen
Mixing Study
Monilia - see Culture Fungus
Mononucleosis Screen
Monospot - see Mononucleosis Screen
Morphine Unconjugated Serum
Motor Neuropathy Panel
MPO
Mucin Clot
Multiple Myeloma Panel
Mumps AB IgG
Mumps AB IgM
Mumps Antibody IgG IgM Panel
Mumps IgG Immune Status - see Mumps AB IgG
Myasthenia Gravis Panel 2
Mycobacteria - see Culture AFB
Mycobacteria By PCR (Lower Respiratory Tract)
Mycoplasma DNA PCR
Mycoplasma Pneumo AB IgG
Mycoplasma Pneumo AB IgM
Myelin Basic Protein
Myeloma Panel
Myeloperoxidase AB
Myoglobin
Myoglobin Quan Urine
Myositis Assessr + JO-1 AB
Mysoline - see Primidone