What Is a Blood Sugar Test Strip?

Blood glucose test strips are a class of consumables that are used in conjunction with blood glucose detectors and are coated with biological enzymes, which can test the presence of certain glucose in peripheral blood by its color change.

The test paper is coated with an ultra-thin conductive layer (commonly used is gold), which is turned into an intricate circuit by laser polishing. In another machine, a chemical coating (containing glucose oxidase or glucose dehydrogenase) is applied to the end of the test strip. This biochemical mixture works by reacting with glucose in the blood of the subject to produce an electrical current. After the test strip dries, go to another machine to create a track to receive the blood sample. At present, some of the common blood glucose test strips on the market are top blood, some are blood on both sides, and some are smeared on the surface. It's because the tracks they opened were different when they were made. Finally, the prepared test strips are cut into individual small test strips and sealed to protect them from moisture and oxidation, affecting the test results. ^[1]

Chinese name: Blood glucose test strip

Foreign name: blood sugar paper

Blood glucose test strip detection principle

The blood glucose test strip consists of two sheets containing sensitive chemical components. Drop the blood on the test area (center of the yellow part), lay the test paper flat for one minute, and rinse the blood. The chemical reaction that occurs when compared with the standard colorimeter will produce different degrees of color change according to the glucose content in the blood. Glucose oxidase and peroxidase on the test paper react with glucose in the blood. The color indicator accompanying the reaction and non-reactive components will appear in the test area.

The working principle of common blood glucose meters: The glucose in the blood reacts with glucose oxidase and potassium ferricyanide fixed on the surface of the test strip to produce gluconic acid and potassium ferricyanide. The glucose meter applies a constant working voltage to the test strip to oxidize potassium ferrocyanide to potassium ferricyanide to generate an oxidation current. The magnitude of the oxidation current is proportional to the glucose concentration. The glucose meter records the magnitude of the oxidation current and converts Show the glucose concentration.

Blood glucose test enzymes

Glucose Oxidase.
Glucose dehydrogenase (PQQ) PQQ-Glucos dehydrogenase.
Glucose dehydrogenase (FAD).
Hexokinase.

Glucose oxidase oxidizes glucose in blood samples to gluconic acid, and presents the electrons released by the oxidation of glucose to the electrode with the participation of oxygen, and reflects the glucose content in the blood by the number of electrons.

Suitable for patients with glucose oxidase: Patients who use maltose-containing drugs intravenously; Patients who take xylose, oral or galactose. Patients not suitable for glucose oxidase: Patients with high uric acid and bilirubin, such as viral hepatitis, toxic hepatitis caused by drugs or alcohol, hemolytic jaundice, malignant anemia, paroxysmal hemoglobinuria, newborn Jaundice, internal bleeding, tumor compression, primary gout, and some hematological diseases, etc. Patients using acetaminophen, salicylic acid or vitamin C are mainly seen in anti-inflammatory and analgesic drugs, such as aspirin; blood oxygen content is not Stable patients, such as asthma, smoking, emphysema, chronic obstructive pulmonary disease and various cardiovascular diseases, patients receiving oxygen therapy, anemia, shock patients, patients using arterial or venous blood tests. In addition, because the test paper easily reacts with oxygen in the air, it should be used up within 3 to 4 months after opening. Patients with low detection frequency need to pay attention to this.

Glucose dehydrogenase is divided into the following two categories according to the different coenzymes used.

1. Glucose dehydrogenase pyrroquinoline quinone coenzyme (GDH-PQQ) detection principle: glucose dehydrogenase oxidizes glucose to gluconolactone. Under the action of PQQ coenzyme, the electrons generated by oxidation are presented to the electrode, and the amount of glucose in the blood is reflected by the number of electrons.

2. Glucose dehydrogenase-nicotinamide adenine dinucleotide coenzyme / flavin adenine dinucleotide (GDH-NAD / FAD) detection principle: basic and glucose dehydrogenase pyrroquinolinequinone coenzyme (GDH-PQQ ) The detection principle is the same, and the coenzymes used are different.

Precautions for blood glucose test strips

For in vitro diagnostic use. Test strips can only be used at 18 to 35 ° C (64 to 95 ° F). Use only fresh fingertip capillary blood, earlobe blood as a blood sample. No venous blood, plasma or serum is used. The test strip can only be used once. Incorrect timing-Leaving the blood sample too long will increase readings. Wiping a blood sample too early will reduce readings. The detection result of very high hematocrit (> 55%) may be 15% lower than the actual value, and the detection result of too low hematocrit (<35%) may be 10% lower than the actual value. Standard color plates may produce color gradation due to different batches. You should refer to the instructions for operation.

Classification of blood glucose test strips

Blood glucose test strips can be divided into six broad categories. Roughly: drip blood glucose test strips, vitality blood glucose test strips, siphon blood glucose test strips, stable blood glucose test strips, steady blood glucose test strips, hand-held blood glucose test strips.

Blood glucose test strips purchase note

When purchasing blood glucose test strips, you must pay attention to: blood glucose test strips and blood glucose meters are used together, what brand and model of your blood glucose meter, the blood glucose test strips should be purchased with the blood glucose test strip products that match the brand model.

In addition, how much blood glucose test strips is not a problem. The important thing is that the quality of blood glucose test strips directly affects the measurement results. Therefore, while paying attention to the price of blood glucose test strips, you should try to buy good quality brand products.

Fast blood glucose paper is only used to monitor blood sugar in diabetic patients, not as a diagnosis. To diagnose diabetes, you must perform an OGTT test to confirm the diagnosis.

How to save blood glucose test strips

The test paper should be kept dry, protected from light and sealed. Blood glucose test strips should be placed in a dry environment, and the suitable temperature is between 10 degrees Celsius and 30 degrees Celsius. Under normal circumstances, the test paper does not need to be stored in the refrigerator, but it is easily affected by moisture to affect the test results. If the indoor temperature is too high in summer, you can put the test paper into a plastic bag, put a desiccant, and put it in the refrigerator to refrigerate. After taking out from the refrigerator before each test, you should wait for the test paper tube to return to room temperature before opening the cover to take the test paper for testing; do not remove the test paper before the test paper tube has reached room temperature to avoid the formation of condensation in the test paper tube.

Ensure that unused test strips are always stored in the original cartridge. Do not distribute test strips in other containers (including old cartridges), and do not mix used test strips in existing test strips. Pay attention to the expiration date of the test strip and make sure that it runs out within the expiration date. Remove the test paper and close the cap immediately. ^[2]