Widal’s Reaction Results
Widal’s Reaction
Definition:
a specific reaction consisting in agglutination of
typhoid bacilli or paratyphoid bacilli when mixed with
serum from a patient having typhoid fever or other
salmonella infection and constituting a test for the
disease .
Usage: to assist to diagnosis typhoid fever or
other salmonella infection.
Analysis
H抗体与O抗体的性质及其消长的意义
抗体类型
体内出
现情况
与正常值比较
O抗体 IgM
出现较早
维持时间短
高
高
低
H抗体 IgG
出现较晚
维持时间长
高
低
高
伤寒的可
能性很大
感染早期 预防接种
O凝集的交 非特异性回忆
叉反应
反应
Observation:
1. Control tube: no agglutination (-)
2. Lowest titer tube: absolutely agglutination (++++)
3. Other tubes:
three quarters agglutination(+++) half agglutination (++)
one quarter agglutination (+)
no agglutination (-)
Judgment:
Agglutination titer: the highest dilution of serum
which appears (++) bacteria agglutination.
Experiment five
Isolation and Identification
of influenza virus
病毒感染的微生物学检查法
In general, diagnostic tests can be
grouped into 3 categories:
direct detection
indirect examination (virus isolation)
serological methods
流感病毒的分离鉴定
Purpose：
To obtain information about microbiological
diagnosis methods of influenza virus
Procedure
Acquiring and managing specimen
Isolation and Identification of influenza virus
serological diagnosis of influenza virus
流感病毒的分离鉴定
标本采集和处理
Throat washing or gargling are obtained within 3
days after infection
Test at once or stored frozen.
Centrifuge the washings 15 min at 3000 rpm,
Harvest 1 ml of supernatant.
Add antibiotic to prevent bacterial contamination.
Patient’s serum
Throat washings or gargling
Treated with penicillin
and streptomycin
血凝抑制实验
Embryonated egg inoculation
(amniotic or allantoic route)
Harvest amniotic and allantoic fluids
Hemagglutination test
+
-
Hemagglutination inhibition test Inoculate to fresh embryos
complement fixation test
after two such passages
the result is negative
Hemagglutination test, HT
MATERIALS
Virus: the allantoic fluid that contains influenza
virus;
physiological saline;
0.5% chicken RBC suspension.
20-well plastic disposable microtiter plates and
glass pipettes.
Hemagglutination test, HT
Materials
(ml)
well No.
1
2
3
4
5
6
7
8
9
10
Saline
0.45 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
Virus
0.05 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
Dilution
1:10 1:20 1:40 1:80 1:160 1:3201:6401:12801:2560 con
0.5%RBC
弃
0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
incubate the plate at room temperature for 30 to 60 min.
Check the agglutination.
Hemagglutination test (HT)
Results
Record the hemagglutination as the followings:
++++ : All the RBC had been agglutinated.
+++ : 75% of RBC had been agglutinated
++ : 50% of RBC had been agglutinated.
+ : 25% of RBC had been agglutinated.
- : No RBC was agglutinated.
Hemagglutination inhibition test (HIT)
MATERIALS
Patient’s serum: deactivated 30 min at 56℃;
influenza virus: 4 HA units;
0.5% chicken RBC suspension;
physiological saline
20-well microtiter plates, pipettes and tubes.
Materials
(ml)
well No.
1
Saline
2
0.9
3
4
5
6
7
8
9
10
0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
弃
Serum
0.1
Dilution
1:10 1:20 1:40 1:80 1:160 1:320 1:640
Virus
0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
0.25 0.25 0.25 0.25 0.25 0.25
弃
0.25
-
-
-
-
-
-
Mix evenly incubation at 37℃ for 1h
0.5%RBC
0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
-
0.25
Mix evenly incubation at 20℃ for 1 h
Result
-
-
-
+
++
+++ ++++ ++++
-
-
Hemagglutination inhibition test
(HIT)
RESULT
Assess hemagglutination as above, the
hemagglutination inhibition (HI) titer is
the reciprocal of the highest dilution of
the patient's serum which shows
complete inhibition of agglutination.