Frequently Asked Questions
1. Each reagent package must be examined before use. Product integrity may be compromised in packages that have been damaged. Inspect the package for the signs of leakage or moisture. If there is evidence of leakage or improper handling, do not use the reagent.
2. Pay attention to the expiration dates and open-container stability days of all the reagents. Be sure not to use expired reagents.
3. Pay attention to the storage temperature of the reagent (different reagents have different requirements, so you need to refer to the reagent label)
4. Do not ingest any reagent. In case of ingestion, seek medical attention promptly.
4.1. Avoid contact with skin. In case of contact, rinse the affected area immediately with ample amount of clean water.
4.2. Avoid contact with eyes. In case of contact, rinse the affected eye immediately with ample amount of clean water and seek medical attention promptly.
Generally, there are two types of expiration dates of reagents:
One is the storage expiration date of the reagent, that is, the final date on which the reagent can be stored under normal storage conditions (without opening the container);
The other is the open-container expiration date of the reagent, that is, the number of days during which the reagent can be used after the container is opened.
Different reagents have different storage expiration dates and open-container expiration dates, as well as different storage and use temperature requirements. You need to refer to the label or instructions manual of the specific reagent.
Urine samples can be stored at room temperature for 2-3 hours without affecting test results, and preservatives are not required. Prolonged room-temperature storage may lead to bacterial proliferation, glucose consumption, increased opacity in photometric assays, and elevated ammonia levels. Centrifugation is mandatory prior to testing. Turbid specimens may interfere with test results. Freezing of urine samples is strictly prohibited.
CSF is collected via lumbar puncture; alternatively, it may be obtained through cisternal or ventricular puncture if clinically indicated. CSF specimens must be transported immediately after collection, as prolonged storage may compromise test validity due to cell degeneration/lysis, resulting in inaccurate cell counts and differentials.
CSF should be aliquoted into 3 sterile tubes in the following sequence:
Note: The order of tubes must not be reversed.
Due to the invasive nature of specimen collection, strict biohazard handling protocols must be observed throughout transportation and testing. Centrifugation is required prior to CSF analysis.
Pleural/peritoneal fluid is obtained via thoracentesis (pleural) or paracentesis (peritoneal). Specimens should be aliquoted into 4 tubes with the following protocols:
Samples must be transported to the laboratory within 30 minutes to prevent cellular degeneration, clot formation, or bacterial autolysis.
1) Hemolyzed/Lipemic/Icteric Specimens:
Dilute specimens with normal saline appropriately and multiply results by the dilution factor.
For severely lipemic specimens: Perform high-speed centrifugation (10,000 RPM × 10 min), aspirate the lower lipid-free serum layer for testing.
2) Suspected High Immunoglobulin/Rheumatoid Factor (RF) Interference:
If saline dilution fails, use absolute ethanol for protein precipitation:
For non-protein analytes (e.g., CREA, UA):
Mix serum with absolute ethanol at 1:1, 2:1, or 3:1 ratios.
Vortex thoroughly, then centrifuge at 10,000 RPM × 10 min.
Aspirate the supernatant for immediate testing.
Validate reaction curve integrity and ensure measured concentration falls within the linear range.
Multiply the result by the dilution factor to obtain the final value.
Manage by test: No calibration required when switching reagent lots.
Manage by lot: Mandatory calibration upon lot change.
Manage by bottle: Calibration parameters are assigned per bottle set. Calibration required upon lot change. No per-bottle calibration within the same lot.
Calibration by bottle: Each reagent bottle requires independent calibration.
BS-2800M / BS-600M Systems:
Scenario 1: Calibration results within acceptable range
Action: Override the alarm directly. The result will be flagged with "Override".Perform recalibration to remove the override flag.
Scenario 2: Calibration failure (out-of-range results)
Action: Reject the current calibration and restart the calibration protocol.
BS-800 System:
Step 1: Disable the 20% coefficient limit in calibration settings.
Step 2: Perform recalibration.
Step 3: If calibration succeeds, restore the original coefficient limit.
BS-2000/BS-430/BS-360E and other systems:
If results are abnormal but calibration completes (marked "FAC"). Recalibrate. If successful, the "FAC" flag will be automatically cleared.
Verify adequate clotting status and confirm sample tube type compatibility.
Calibration Validation:
Compare calibration R0 with factory-set values.
Reagent Status:
Check expiration date and on-board stability.
Instrument Errors:
Review system alerts.
Clinical Analysis:
Understanding the patient's clinical information may be caused by certain physiological factors.
Twin test mode allows simultaneous measurement of Hb and HbA1c using a shared reagent. Requires 1× R1 + 1× R2 (total 2 reagents) for both tests.
Non-twin mode requires separate reagents for each test. Hb: Single reagent (1× R1). HbA1c: Dual reagents (1× R1 + 1× R2). Total reagents needed: 3 (2× R1 + 1× R2).
Parameter Settings:
Non-twin test mode: Uses parameter Hb-1.
Twin test mode:
With centrifugation: Parameter Hb-2.
Without centrifugation: Parameter Hb-3.
The BS-2800M lamp has a two-tier alert system based on usage hours:
After 2000 hours:
A daily startup alert will appear, indicating "The lamp is nearing end of life. Prepare for replacement."
After 2400 hours:
A daily startup alert will escalate to "The lamp has reached end of life. Replace immediately."
Abnormal performance:
If abnormal fluctuations in reaction curves occur frequently, consider replacing the lamp even before reaching the hourly thresholds.
Under normal operating conditions, analysis cuvettes do not require routine replacement. The system automatically flags faulty cuvettes during the cuvette self-test process.
Replacement protocol:
If a cuvette is flagged, clean the cuvette thoroughly and rerun the self-test. If the "Cuvette Error" alert remains triggered after cleaning, replace the flagged cuvette immediately.
For reagents such as CO2, ALP, UREA, TP, and Mg, which are strongly alkaline and prone to absorbing CO2 from the air, causing pH changes and reagent deterioration.
Add a special tube to the reagent bottle to minimize its reaction with atmospheric CO2.
If the usage volume is small, immediately recap the reagent bottle after daily testing, store it in the refrigerator, and return it to the reagent compartment before use.
Hemolysis is a common interfering factor in clinical biochemical tests, which can cause either falsely elevated or decreased results in various biochemical tests.
Test assays with elevated results:
AST, LDH, CK, ALT, Ca2+, K+, TP, CHE
Test assays with decreased results:
GLU, γ-GT, P, Na
CK has 4 isoenzyme forms: the mitochondrial isoenzyme CK-Mt found in mitochondria, and 3 cytoplasmic isoenzymes. The latter are dimers composed of brain-type (B) and muscle-type (M) subunits, specifically CK-MM, CK-MB, and CK-BB.
CK-MB and CK-MM are primarily found in various muscle tissues. Skeletal muscle contains 98%-99% CK-MM and 1%-2% CK-MB. In myocardial tissue, CK content is second only to skeletal muscle and brain, with approximately 80% CK-MM and 10%-20% CK-MB. CK-BB is mainly present in human brain tissue.
1) Elevated CK-BB in Serum
When using the immunoinhibition method for CK-MB detection, the M subunit is inhibited while the B subunit remains active. If serum contains significant CK-BB (e.g., due to brain injury or increased blood-brain barrier permeability), this may cause CK-MB activity > total CK activity.
2) Methodological Interference
In some cancer patients, tumor-derived immunoglobulins may react with assay reagents as substrates or coenzymes, leading to falsely elevated CK-MB levels.
3) Macro CK (Macroenzyme CK)
Macro CK (Macro CK) giant molecular enzyme is not easy to be excreted in the body and not easy to be engulfed and degraded by macrophages, and because it has a long half-life, it has a long retention time in the blood, and it is often easy to cause false increase in enzyme activity and changes in isoenzymes in routine biochemical tests. Giant CK is not inhibited by anti-CK-M subunit antibodies, resulting in a false increase in CK-MB activity.
1) Isoenzyme electrophoresis - Can identify false CK-MB elevation caused by CK-BB or macro-CK. Electrophoresis will show characteristic bands for CK-BB, macro-CK1, and macro-CK2.
2) Monoclonal antibody immunoassay for CK-MB mass - If isoenzyme electrophoresis is unavailable, measure CK-MB mass to confirm true CK-MB elevation. This method uses CK-MB monoclonal antibodies with no cross-reactivity to CK-BB or CK-MM, unaffected by other serum enzymes/proteins. It has higher specificity and sensitivity than immunoinhibition-based CK-MB activity assays. Normal CK-MB mass suggests interference in immunoinhibition results.
3) Heat inactivation test - Incubate suspicious serum at 45°C for 20 minutes, then measure residual CK activity. CK-MB and CK-BB are nearly fully inactivated, while macro-CK remains unaffected.
1) Methodology. Due to the faster reverse reaction rate, the measured value is twice that of the forward reaction. Generally, LDH is measured using the forward reaction (LDH-L method), while α-HBDH measurement corresponds to the reverse reaction. Therefore, although there are cases where α-HBDH is higher than LDH-L, it should not exceed LDH-L × 2.
2) Substrate differences. HBDH measures the combined activity of LDH1 and LDH2. Because a different substrate is used, it does not equal the activity of LDH1 and LDH2 when lactate is the substrate. Instead, it reflects the reaction of the LDH H-subunit acting on an alternative substrate.
3) The optimal pH varies among different LDH isoenzymes. When measuring total LDH, it does not necessarily represent the sum of the maximum activities of all LDH isoenzymes.
1) Elevated blood β2MG with normal urine levels – Mainly due to decreased glomerular filtration function, commonly seen in acute/chronic nephritis, renal failure, etc.
2) Normal blood β2MG with elevated urine levels – Primarily caused by significant impairment of tubular reabsorption, observed in congenital proximal tubule dysfunction, Fanconi syndrome, chronic cadmium poisoning, Wilson’s disease, renal transplant rejection, etc.
3) Elevated blood and urine β2MG – Typically results from either overproduction in certain body sites or combined glomerular/tubular damage, often seen in malignancies (e.g., primary liver cancer, lung cancer, myeloma), systemic autoimmune diseases (e.g., SLE, hemolytic anemia), chronic hepatitis, diabetes mellitus, etc.
Blood glucose is not glycosylated hemoglobin, blood glucose is simply the amount of glucose in the blood at a point in time. Blood glucose can be affected by diet, exercise, etc.; Glycosylated hemoglobin reflects the patient's average blood glucose level over the last 8-12 weeks. Elevated glycosylated hemoglobin indicates poor glycemic control in the past 2-3 months, but glycosylated hemoglobin can be affected by factors such as test methods, the presence of blood disorders, and age. In addition, glycosylated hemoglobin does not reflect instantaneous blood glucose levels and fluctuations in blood glucose, nor does it determine whether hypoglycemia has occurred during treatment.
Alkaline phosphatase (ALP) is widely distributed in human organs, with the highest concentrations in the liver, followed by the kidneys, bones, intestines, and placenta.
Physiological Causes:
In most cases, elevated ALP in pregnant women is normal. Clinical observations show that ALP levels in the ninth month of pregnancy can be 2–3 times higher than standard values.
This increase is due to rapid fetal bone development in the mid-to-late stages of pregnancy, which releases large amounts of ALP.
As the fetus grows, its respiration and waste excretion rely entirely on the mother, increasing maternal metabolic demand and liver workload. Even in healthy pregnancies, some liver function markers (including ALP) may rise.
A high-fat diet during pregnancy may also temporarily elevate ALP.
Pathological Causes:
Elevated ALP could also indicate underlying conditions such as:
Bone disorders (e.g., Paget’s disease)
Hepatobiliary diseases (e.g., cholestasis, hepatitis)
Hyperparathyroidism
Further evaluation is needed if ALP levels are disproportionately high or accompanied by other abnormal symptoms/lab results.
Note: Need to consult a doctor to rule out pathological factors.
During normal growth periods, the increased secretion of alkaline phosphatase by osteoblasts due to bone growth causes ALP activity in growing children to be approximately 3 times higher than in healthy adults.
1) Definition and Measurement Targets
GSP: Refers to the total products formed by glucose binding to various serum proteins (e.g., albumin, globulins) through non-enzymatic reactions. It reflects the overall level of glycated proteins in the serum.
GA: Specifically measures the proportion of glucose-bound albumin, excluding interference from other proteins.
2) Time Range
Both reflect 2–3 weeks of average blood glucose levels, as albumin has a half-life of 17–20 days. However, GA is more precise because it focuses solely on albumin-related glucose data, whereas GSP may be
influenced by varying metabolic cycles of other serum proteins.
3) Detection Methods
GSP: Measures ketoamine compounds in total glycated serum proteins. Results can be affected by total protein concentration, bilirubin, chylomicrons, and other factors.
GA: Calculates the percentage of glycated albumin relative to total albumin, eliminating the impact of albumin concentration changes. This method offers higher specificity.
4) Clinical Applications
GSP: Gradually being replaced by GA due to lower precision, and is now mainly used for rough assessments of short-term glucose fluctuations.
GA: Preferred for specific populations, such as patients with anemia, late-stage pregnancy, or hemoglobin abnormalities (e.g., thalassemia), as it is unaffected by red blood cell lifespan. Additionally, GA responds faster to glucose changes than HbA1c, allowing earlier evaluation of glucose-lowering therapy effectiveness.