FAQ

Frequently Asked Questions

How often do I need to recalibrate my HemoCue® Analyzer?

The HemoCue® Glucose Analyzers are factory calibrated and needs no further calibration.

How often should I clean the cuvette holder?

The cuvette holder should be cleaned after being used, on the days of testing,
with alcohol or a mild soap solution after being completely removed from the
analyzer. The holder must be completely dry before being reinserted in the
analyzer.

How often should I clean the cover glasses of the optronic unit?

Cleaning frequency may depend on the amount of samples being analyzed and/or local regulations regarding maintenance. Clean the coverglasses of the optronic unit with the HemoCue® Cleaner.

Warning! Do not open the optronic assembly!

Follow the directions in the HemoCue® Cleaner instructions for use.

  1. Turn the analyzer off and remove the cuvette holder as described in the operating manual
  2. Remove the cleaner from the package and insert into the analyzer
  3. Move the cleaner over the entire optronic unit
  4. Inspect the cleaner. If it is dirty, repeat the procedure with a new cleaner
  5. Wait 15 minutes before replacing the cuvette holder
  6. Check the system as required

Note! Dispose of the cleaner as potentially infectious waste. Do not reuse the cleaner.

How often should I clean my control cuvette?

HemoCue® B-Glucose:
Clean the control cuvette when the value deviates from the assigned value
(± limits).

Cleaning the control cuvette:

  1. Dampen a fresh cotton swab with alcohol or isopropanol (without additives).
  2. Clean the control cuvette filter gently but thoroughly.
  3. Wipe dry with a fresh, dry cotton swab.
  4. Visually check that the control cuvette filter is clean. If not, repeat the
    procedure.

How should I store my HemoCue® Glucose Microcuvettes?

The reagents contained within the HemoCue® Glucose Microcuvettes are moisture and temperature sensitive. The color of the reagents in dry form is faint yellow.
Improper storage may give cuvettes a distinctive brown or blue-brown color and
these cuvettes should not be used. As this test method relies on photometric
measurement, care should be taken not to hold the cuvette by the filling end. Also take care to wipe away all contaminating substances from the outer surface of the cuvette. All unused cuvettes must remain in the original package. Use the HemoCue® Glucose Microcuvettes prior to their expiry date. The expiry date is printed on each package.

Storage for HemoCue® Glucose Microcuvettes
The storage conditions for the microcuvettes are stated in the Package Insert. Always read the Package Insert before use. Go to Technical Specifications to see storage conditions.

I lost the control cuvette, what do I do?

HemoCue® B-Glucose:
The control cuvette is specific to thye analyzer, if it is lost, contact your local
HemoCue® distributor for replacement.

The control cuvette gives erroneous results, what do I do?

HemoCue® B-Glucose:
The control cuvette is an optical interference filter, which is used to verify that the calibration is stable and does not change from day to day. When you check the received value, it should not exceed the established range on the control cuvette card.

Glucose: ±0.3 mmol/L (6 mg/dL).

Make sure that the analyzer and the control cuvette are clean.

For further information read the Troubleshooting Guide in the relevant Operating Manual.

The control cuvette is cracked or damaged, what do I do?

HemoCue® B-Glucose:
The control cuvette is specific to the analyzer, if it is cracked or damaged, contact your local HemoCue® distributor for replacement.

The liquid control solution values are too high or too low, what do I do?

The system may be controlled with whole blood, hemolysate, plasma, serum or
water based controls.

Note! Most whole blood controls for glucose containing fixed erythrocytes, whether human or animal, cannot be used since the erythrocytes cannot be haemolyzed. Considerable variability exists in different types and production methods for such controls. For these reasons use controls recommended by HemoCue®. Contact HemoCue® AB or your local distributor for more information.

Check the expiration date and storage of the liquid control and microcuvettes. They might be too old, damaged or improperly stored.

For further information, please check the relevant Operating Manual.

What can I do if the analyzer gives an error code?

If an error occur pleaser refer to the Troubleshooting Guide in the relevant Operating Manual.

What is good quality control?

Quality control testing, preferably performed regularly, verifies the function of the system and guarantees reliable patient results.The frequency of quality control testing will depend on factors such as patient sample frequency and/or local regulations.

Control cuvette
The HemoCue® Glucose 201/201+ Analyzer has an internal electronic “SELFTEST”. Every time the analyzer is turned on, it will automatically verify the performance of the optical unit of the analyzer. This test is performed every second hour if the analyzer is left turned on.

The function of the HemoCue® B-Glucose Analyzer can be checked on the days of testing by measuring the enclosed control cuvette. The control cuvette, which is an optical interference filter, is used to verify that the calibration is stable i.e. not changing from day to day. The measured value should not deviate from the assigned value (±limits) on the control cuvette card.

The control cuvette is specific for each analyzer i.e. the serial number on the
control cuvette corresponds to the serial number of the analyzer.

Liquid control solutions
It is good laboratory practice to check the function of the HemoCue® system daily before use. A control of the complete system i.e. both analyzer and microcuvette, can be performed with liquid control solutions.

The HemoCue® systems are developed to give correct results on fresh whole blood.
Commercially available quality control solutions, however, might differ significantly from fresh whole blood. They vary in composition, are stabilized, and contain preservatives or other additives that might cause erroneous readings. It is therefore recommended to use quality control solutions with assayed values specific for the HemoCue® system. For suitable control solutions, see Quality Controls.

Control solution results should fall within assigned ranges. If results are out of range, local guidelines for failed quality control testing should be followed prior to any patient testing.

External quality control (Proficiency testing)
External quality control testing can be local, national or international. Specimens with unknown values are sent out to participants for analysis. Personnel who routinely test patient samples are to test the external control solution in the same way as they test the real patient samples. The results are then usually reported as acceptable or unacceptable in terms of difference from the mean between results reported by participants and reference laboratories.

Contact national authorities for suitable proficiency testing programs.

What level of control solution shall I use?

It is practical and relevant to use a control at a level in the same range as your most common patient result.

Please follow your local quality control regulations.

Why is there a difference between HemoCue® Glucose system results compared with laboratory results?

A number of factors may influence the outcome of a comparison between two
glucose methods. For best results the following factors should be considered before starting an evaluation:

– glycolysis
– sample type (venous, arterial, capillary, plasma or whole blood)
– analytical method

Glycolysis:
When a blood sample is collected and sent to the laboratory in a tube, the cells in the sample will continue to consume glucose. The glucose concentration will decrease with approximately 0.5 mmol/L per hour (9 mg/dL per hour) depending on hematocrit, temperature and mixing.

Common preservatives, like Sodium Fluoride, will not fully stop the glycolysis until two hours have elapsed. If the sample is not immediately analyzed, stored on ice or immediately centrifuged, it is likely that the result will be affected by glycolysis, i.e. too low.

Sample type:
In a non-fasting state, arterial and capillary glucose values are approximately 8%
higher than venous blood glucose values. In a fasting state these differences may
generally be ignored.

The HemoCue® Glucose systems measure the glucose concentration in whole blood. Many laboratory methods measure the glucose concentration in plasma. At normal hematocrit values plasma glucose is 10-15% higher than whole blood glucose.

Analytical method:
There is no international accepted reference method for the determination of glucose. Variations in routines for calibration may cause differences between methods. The HemoCue® Glucose systems are factory calibrated against a wet chemistry glucose dehydrogenase method.

The liquid control solution container has been stored at room temperature for 24 hours, what can I do?

It is not recommended to use products that are incorrectly stored. Most Liquid Control Solutions must be stored cold. Please call your local representative for further information.

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