Frequently Asked Questions

What is the SPOTCHEM EZ's measurement principle?

What is end-point and reaction-rate assay?

What type of samples can be run on the SPOTCHEM EZ?

How does the calibration card work, why is the calibration performed and how frequently must calibration take place?

Should QC be run on the SPOTCHEM EZ?

How is QC run on the SPOTCHEM EZ?

How does the sample get from the serum/plasma/centrifuge cup to the reagent strip?

How much maintenance does the SPOTCHEM EZ require?

Does the SPOTCHEM EZ require a water source or waste drain?

Q: What is the SPOTCHEM EZ's measurement principle?

A: Reflectance photometry. The light emitted from an LED becomes monochromatic light of a certain wavelength after passing through an optical fiber (Five different types of optical filters are provided, and the optimum wavelength is selected for each test item). Monochromatic light is separated and transmitted to the photometry section of each channel by ten optical fibers. In each photometry section, the monochromatic light transmitted by the optical fibers is irradiated on the reagent fields, which has a color reaction after sampling. Its reflected light is read with 2 photodiodes, and the system calculates measurement results by end-point assay (EPA) or reaction-rate assay (RRA).

Q: What is end-point and reaction-rate assay?

A: End-point assay involves a reagent blank measurement and a second absorbance reading after the reaction is complete. Reaction-rate assay (usually used for enzymes) involves the reading of several absorbance values over a specified period. The rate of the reaction is calculated from the change in absorbance as a function of time. A modified rate reaction can be measured beginning with a reagent blank reading followed by 2 absorbance readings at a specified interval.

Q: What type of samples can be run on the SPOTCHEM EZ?

A: Serum, heparinized plasma and heparinized whole blood.

Q: How does the calibration card work, why is the calibration performed and how frequently must calibration take place?

A: The calibration on the SPOTCHEM is performed using a magnetic card. The calibration is necessary to maintain measurement accuracy. The four magnetic strips on the card hold calibration information and are swiped two times each to ensure that the calibration information has been successfully transferred into the software. The calibration must be performed once per box of reagent strips. The box of reagent strips must be calibrated with the card that was supplied in the box.

Q: Should QC be run on the SPOTCHEM EZ?

A: Yes, ARKRAY recommends that QC be run on the Spotchem daily and when using a new lot, shipment or box of reagent strips.

Q: How is QC run on the SPOTCHEM EZ?

A: QC is run on the Spotchem in the same manner as a whole blood, serum or plasma patient sample. Press 1 for measure and 1 to enter the control ID. Enter the control ID and press enter. Place approx. 4 drops of the control sera in a serum/plasma Spotchem cup or 250uL of control sera in a centrifuge cup; place the cup in the appropriate holder, a tip in the tip holder and reagent strips on the reagent table. Press run. The control results will print out like patient results with a normal patient range (not the control range) below the results.

Q: How does the sample get from the serum/plasma/centrifuge cup to the reagent strip?

A: The SPOTCHEM EZ has a continuous batch sampling nozzle. The nozzle moves side to side and up and down to go from the tip, to the sample cup to the reagent strip. The nozzle automatically removes the tip and places it in the tip waste case. The aspirating function of the nozzle is controlled by a plunger pump with seal. The plunger pump is a glass chamber filled with air. The plunger has a seal on the end of it and moves side to side within the chamber to facilitate aspiration and dispense of the sample.

Q: How much maintenance does the SPOTCHEM EZ require?

A: The SPOTCHEM EZ requires minimal maintenance. The daily maintenance consists of cleaning the reagent table, tip waste case and protective cover. Weekly maintenance consists of cleaning the black and white plates and the rubber plate. Cleaning of the optical windows should be performed every 6 months and/or 2,000 measurements or if error occurs. The nozzle should be cleaned yearly and/or every 10,000 measurements or as needed. The nozzle and paper should be replaced as needed.

Q: Does the SPOTCHEM EZ require a water source or waste drain?

A: No.