Zinc is an essential trace metal involved in a multitude of biological pathways including cell growth and differentiation, nucleic acid metabolism, signal transduction, and neurological functions. It binds a variety of proteins and acts as a cofactor in many enzymes such as the carbon dioxide regulator, carbonic anhydrase, and the peptide hydrolyzing enzyme, carboxypeptidase. Zinc is important to many enzymatic reactions, transcription factors, and structural proteins. Zinc deficiency results in many clinical manifestations including loss of appetite, impaired immunity, growth retardation, weight loss, poor wound healing, diarrhea, and mental fatigue. Disease states associated with zinc malabsorption include chronic liver disease, chronic kidney disease, sickle cell disease, diabetes, and gastrointestinal disorders.

Zinc Assay Kit provides a simple, reproducible, and sensitive tool of measuring Zinc concentration in plasma, serum, cell lysates, saliva, urine, and other biological liquid samples. Samples are deproteinized to release bound zinc. Free zinc forms a complex with the Chromogenic Agent to produce a bright red color, which is then measured at an absorbance of 560 nm. The optical density measured at 560 nm is directly proportional to

the concentration of total Zinc present in the sample. Cofactors are added into the assay to mask other metal like Fe, Cu, Ni, Co interferences.

• Microplate reader capable of measuring absorbance at 560 nm
• Precision pipettes to deliver 2 µL to 1 mL volumes
• Tubes to prepare sample dilutions
• Multi-channel pipettes to deliver 20 µL to 200 µL volumes
• 15 ml, 50ml tubes
• MilliQ water or another type of double distilled water (ddH₂O)
• 1 M K₂CO₃ or 1 M NaOH
• Concentrated HCl
• pH paper

1. Add 50 µL of the diluted Zinc Standards or samples to the 96-well microtiter plate.
2. Initiate the reaction by adding 200 µL Working Solution to all wells. Carefully shake the plate for a few seconds to mix.
3. Incubate the plate for 5 minutes at room temperature with mixing in the dark.
4. Measure the absorbance at 560 nm using a plate reader.