1、 Overview
Tuberculosis- γ The principle of interferon release test (TB-IGRA) is as follows:
The specific stimulating antigens "esat6 and cfp10" are unique fragments of pathogenic Mycobacterium tuberculosis but not of BCG and other mycobacteria.
Mycobacterium tuberculosis infected persons have specific T lymphocytes for each antigen, which can recognize and present these antigens, stimulate the proliferation of T lymphocytes, and release cytokines, such as IFN- γ。 Specific IFN released in vitro can be quantitatively detected by ELISA- γ, So as to judge whether it is infected with Mycobacterium tuberculosis.
2、TB-IGRAprocess
A、Schematic diagram of stimulation process:
B、Schematic diagram of detection process:
3、 Recommended usage(ELISA)
A、Amount of stimulator: 1ug/tube
B、Recommendations for use of ELISA reagents:
C6H4:1:1000Coated with antibody overnight. Washing and sealing. Sampling100ul,Joining at the same time20ul 1:2000Diluted8A11-F(ab)2-HRP,Washing, color development and termination.
C、Quantitative range of standard
Take the mean absorbance of the calibration sample as the independent variable(X),Its correspondingIFN-γContent of(12.5 pg/ml~400 pg/ml)Is a dependent variable(Y),The linear regression equation is obtained by power fittingy=167.64x0.9554,The data and schematic diagram are as follows:
校準(zhǔn)品值 | 2.294 | 1.277 | 0.621 | 0.275 | 0.136 | 0.065 |
校準(zhǔn)品IFN-γ含量 (單位:pg/ml) | 400 | 200 | 100 | 50 | 25 | 12.5 |
4、 Result judgment recommendation
Test culture tube (T) content value=T, background control culture tube (N) content value=N, positive control culture tube (P) content value=P (unit: pg/ml)
N | P-N | T-N | 結(jié)果判定 | 結(jié)果解釋 |
≤400 | 任何值 | ≥14 并且≥(N/4) | 陽性 | 感染結(jié)核分枝桿菌 (結(jié)核活動(dòng)期感染、潛伏感染或隱性感染) |
≥20 | <14 | 陰性 | 未感染結(jié)核分枝桿菌 | |
≥20 | ≥14但<(N/4) | 陰性 | ||
<20 | <14 | 不確定 | 不能確定是否感染結(jié)核分枝桿菌 | |
<20 | ≥14但<(N/4) | 不確定 | ||
>400 | 任何值 | 任何值 | 不確定 |
5、 Performance evaluation
*Refer to Australian QFT reagent
6、 Raw material information