Syphilis USR Test

Inactivated serum responsiveness test (USR). This test is generally used for diagnostic screening and epidemiological investigation of syphilis. The USR test is a modified VDRL test method. The formulated VDBL antigen was centrifuged and the pellet was resuspended in ethylenediaminetetraacetic acid (EDTA), choline chloride and phosphate buffer. Since EDTA can make the antigen invariant within 12 months, choline chloride can play a role of "chemical inactivation". Therefore, serum samples do not need to be inactivated by heat, and the antigen does not have to be prepared every day. The refrigerator can be used at 4 ° C ~ 8 ° C. It is easier to save for 12 months. Basic Information Specialist classification: Infectious disease examination and classification: blood examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Normal value: no Above normal: negative: normal. Positive: After syphilis or syphilis infection, the specificity of this test was 0.99 (99%), and the false positive rate was about 0.003 (0.3%). Patients with syphilis who are treated later may be positive for life. Tips: Do not eat too greasy, high-protein foods the day before the blood draw, avoid heavy drinking. The alcohol content in the blood directly affects the test results. Normal value negative. Clinical significance Abnormal results: After positive syphilis or syphilis infection, the specificity of this test was 0.99 (99%), and the false positive rate was about 0.003 (0.3%). Patients with syphilis who are treated later may be positive for life. Need to check the crowd: 1. People with symptoms of hard squatting on the epidermis of the skin. 2. People who have lived unclean sex. Precautions Preparation before inspection: 1, do not eat too greasy, high-protein food the day before the blood, to avoid heavy drinking. The alcohol content in the blood directly affects the test results. 2. After 8 pm on the day before the physical examination, fasting should be done to avoid affecting the detection of indicators such as blood glucose in the second sky. 3, should relax when taking blood, to avoid the contraction of blood vessels caused by fear, increase the difficulty of blood collection; guests with a history of fainting, please explain in advance, we will make special arrangements. Requirements for inspection: 1. After blood is drawn, local compression is required at the pinhole for 3-5 minutes to stop bleeding. Note: Do not rub, so as not to cause subcutaneous hematoma. 2, the pressing time should be sufficient. There is a difference in clotting time for each person, and some people need a little longer to clotting. Therefore, when the surface of the skin appears to be bleeding, the compression is stopped immediately, and the blood may be infiltrated into the skin due to incomplete hemostasis. Therefore, the compression time is longer to completely stop bleeding. If there is a tendency to bleed, the compression time should be extended. 3, after the blood draw symptoms of fainting such as: dizziness, vertigo, fatigue, etc. should immediately lie down, drink a small amount of syrup, and then undergo a physical examination after the symptoms are relieved. 4. If there is localized congestion, use a warm towel after 24 hours to promote absorption. Not suitable for people: There is no inappropriate crowd. Inspection process The USR test is a modified VDRL test method. The formulated VDBL antigen was centrifuged and the pellet was resuspended in ethylenediaminetetraacetic acid (EDTA), choline chloride and phosphate buffer. Since EDTA can make the antigen invariant within 12 months, choline chloride can play a role of "chemical inactivation". Therefore, serum samples do not need to be inactivated by heat, and the antigen does not have to be prepared every day. The refrigerator can be used at 4 ° C ~ 8 ° C. It is easier to save for 12 months. material: 1. USR kit: (1) USR antigen; (2) disposable plastic (glass) reaction plate with a diameter of 14 mm; (3) 45 drops of ± 1 drop/mL standard needle; (4) standard photo of USR reaction results . 2. Adjustable blood clot oscillator. method: 1.USB qualitative test: (1) Pipetting 0.05mL of serum into the circle of the reaction plate to spread the serum to the entire inner circle; (2) adding 1 drop of antigen to each specimen with a standard needle; (3) shaking by hand or by shaking Shake for 4 minutes, 180 times ± 5 times / minute, immediately observe with the naked eye or 100 times under the microscope. Results: (1) There are large or medium-sized flocs, the solution is clear... 3+~4+ strong positive reaction; (2) the floc is relatively small, the suspension is clearer... 2+ positive reaction; 3) floc is small, evenly distributed, liquid turbidity... 1+ weak positive reaction; (4) antigenic particles are slightly thicker...±suspicious, generally genus; (5) antigenic particles are uniform, needle-like is small...-negative reaction. 2. USR quantitative test: Specimens that are positive, weakly positive, or suspicious in qualitative tests are subject to quantitative testing. The former is to determine antibody titers and the latter to exclude "pre-banding." (1) Add 50 μL of isotonic saline to each well of the reaction plate from 2 to 6 wells. (2) Pipette 50 μL of serum sample into the first well as the original sera, then add 50 μL of serum to the second well and mix, soak 50 μL to the third well, dilute to the 6th well, and discard 50 μL, then 6 The pore dilution is: primary, 1:2, 1:4, 1:8, 1:16, 1:32, and if necessary, continue to dilute to 1:64, 1:128 or higher. (3) Add 1 drop of antigen to each dilution. (4) Oscillation speed, time and results were observed for the same qualitative test. Not suitable for the crowd There are no special taboos. Adverse reactions and risks There are no related complications and hazards.

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