SPECIFICITY
The r-Metolachlor Plate Kit is specific for metolachlor with very slight reactivity with a limited number of closely related compounds. The following table shows the relative values for 50% Bo and the % cross-reactivity versus metolachlor. All concentrations are in parts per billion (ppb).

Compound                     50% B0                 % Cross Reactivity
Metolachlor                    0.50                                 100
Acetochlor                      95                                     0.53
Propachlor                     100                                   0.50
Alachlor                          450                                   0.11

ASSAY PRINCIPLES
The r-Metolachlor Plate Kit uses polyclonal antibodies that bind both r-Metolachlor and an r-Metolachlor-enzyme conjugate. r-Metolachlor in the sample competes with r-Metolachlor-enzyme conjugate for a limited number of antibody binding sites. Antibodies, which bind r-Metolachlor compounds, are immobilized to the inside of the test wells. In the assay procedure, you will:

•Add a sample containing r-Metolachlor to a test well, followed by r-Metolachlor-enzyme conjugate. The conjugate competes with any r-Metolachlor in the sample for the same antibody binding sites.
•Wash away any unbound molecules, after you incubate this mixture for 60 minutes.
•Add clear substrate solution to each well. In the presence of bound r-Metolachlor-enzyme conjugate, the substrate is converted to a blue compound. One enzyme molecule can convert many substrate molecules.

Since the same number of antibody binding sites are available in every well, and each well receives the same number of r-Metolachlor-enzyme conjugate molecules, a sample containing a low concentration of r-Metolachlor allows the antibody to bind many r-Metolachlor-enzyme conjugate molecules. The result is a dark blue solution.
Conversely, a high concentration of r-Metolachlor allows fewer r-Metolachlor-enzyme conjugate molecules to be bound by the antibodies, resulting in a lighter blue solution.

NOTE: Color is inversely proportional to r-Metolachlor concentration.
Darker color = Lower concentration
Lighter color = Higher concentration

PRECAUTIONS
1.   Each reagent is optimized for use in the 2,4-D Tube Kit. Do not substitute reagents from any other manufacturer into the test kit. Do not combine reagents from other 2,4-D Tube Kits with different Lot numbers.
2.   Dilution or adulteration of reagents or samples not called for in the procedure may result in inaccurate results.
3.   Do not use reagents after the expiration date.
4.   Reagents should be brought to room temperature, 20 – 28ºC (62 – 82ºF) prior to use. Avoid prolonged (> 24 hours) storage at room temperature.
5.   The Stop Solution is 1N hydrochloric acid. Avoid contact with skin and mucous membranes. Immediately clean up any spills and wash the area with copious amounts of water. If contact should occur, immediately flush with copious amounts of water.