This involves the transfer of blood from one individual to another of the same blood group. A+ blood group person can only donate to A+, this is because both posses the same antibody. A person with blood group O+ (rhesus) can donate blood to A+, B+ and AB+ and O+. This is because O+ has antibody to donate to all the blood group (A, B, AB) with O.
AB as a universal recipient can accept blood from all the four types of blood group. The present of antibody A and B can stimulate the reaction. NOTE Rhesus Negative Person cannot transfuse blood to Rhesus negative.
Blood Transfusion Data
|Blood Group||Transfuse to||accept from|
|O+||A+, B+,AB+||A+, B+, AB+|
|AB+||AB+||AB+,O+, A+, B+|
NOTE- Before a blood is transfuse, it should be cross marched and screened for HIV, Hepatitis etc.
Bleeding that occur in the intestinal wall can be caused by Gastric and duodenal ulcer .other causes include reflux Oesophagitis, Mallory-weise Syndrome, Gastric carcinoma and Oesophagial Varices.
Blood from these lesions is usually broken down or digested before passing out in faeces and is used in the investigation of gastric or duodenal ulcer.
Massive bleeding can occur in diverticular disease or Ischaemic colitis. Other causes are rectal or caecal carcinomas and heamorrhoids. Blood from this lesion is usually passed out intact in faeces and can be seen with naked eye or microscope.
Menstrual contamination can also result in the presence of blood in faeces.
Occult blood test is performed to detect bleeding in the upper gastric intestinal track (GIT) and is used in the investigation of peptic ulcer.
Principle- Haemoglobin or its iron derivative catalyzes the oxidation of as non-carcinogenic chromagen (JDL chromagen) to a pink colored in the presence of the perioxide. JDL chromagen is non-carcinogenic, non-reliable in the detection of occult blood in faeces.
Content 60Tests 100Tests
1 Solution A 3.0mls 5.0mls
2 Solution B 3.0mls 5.0mls
3 Thick glossy paper 60pcs 100pcs
4 Buffer (negative control) 10mls 10mls
- Emulsify little faeces in 2 drops of buffer on the glossy side of paper provided
Used the buffer provided
- Add 1 drop of Solution A
- Add 1 drop of Solution B
- Wait for 2 minutes
- Observe colour reaction.
Result-Positive result-Pink color Develop Negative result-No pink color develop.
NOTE-In case of color failure even with positive control; activate solution A with 0.01ml (small drop) of hydrogen perioxide (20 volume).
CONTROL- positive: prepare fresh by adding 0.05mls (1 drop of blood to 2000mls of water.
Negative Control: use the buffer provide as negative control.
- Discard Solution B when it Turns pink
- Avoid using blood contaminated water or material.
- Allow 2 minute for full color development.
FOB (Fecal Occult Blood)
One Step fecal Occult blood test strip this is a rapid chromatographic immunoassay for the qualitative detection of human occult blood.
PRINCIPLE- This explain the qualitative and lateral flow immunoassay for the defection of human occult blood in faeces. The membrane of the strip is precoated with anti-hemoglobin antibody on the test line region of the strip.
During testing, the specimen reacts with the particles coated with anti-hemoglobin antibody. The mixture migrates upward on the membrane by capillary action to react with anti-hemoglobin antibody on the membrane and generate a colored line. The presence of this colored line in the test region indicate positive result while its absence indicate a negative result.
- Alcohol, Aspirin and other medication taken in excess may cause gastrointestinal irritation resulting in occult bleeding. Such substances should be taken in for 48 hour before testing.
- Specimen should not be collected from patient during or within menstrual period or a person suffering from bleeding hemorrhoids
- The specimen are carefully handled to avoid been infected.
- Observe standard procedures for proper disposal was maintained
- Protective clothing’s were put on while carrying out the practical.
This test was carried out using febrile antigen kit which contain reagent for the determination of antibodies against febrile antigen. The febrile kit contain 8 antigen
Antigen AO and AH
BO and BH
CO and CH
DO and DH
NOTE Antigen O is blue while H is pale red Antigen A,B and C are paratyphoid and D is the salmonella typhi or Brucella typhi the Typhoids.
(1)Principle-The cromatest stained antigen are suspension of kill bacteria prepared for the detection and semi-quantilation by agglutination in either side or tube of human serum. Agglutinue, a group of antibody developed during some febrile infections such as brucellosis, samonellosis and certain rickettsiosis.
The Assay is prepared by testing the stained antigens-Somatic blue flagella red against unknown samples. The presence or absence of a visible agglutination is usually related with the presence or absence of the corresponding homologues antibody in the sample tested.
The febrile Antigen stabilized suspension of stained killed bacteria in a buffer solution.
- Glass or white test cards
- Saline solution (Nacl 0.6%)
- Disposable stirrer
- Thermostatic bath (30-50%)
- Test tubes (12 x 100mm)
- Automatic pipette
- Mechanical rotator, adjustable at 100 r.p.m.
PROCEDURE (Quantitative test)
- Bring the test reagent and sample to room temperature.
- Resuspened the antigen vial gently. Aspirate dropper several times to obtain a thorough mixture.
- Place 50ml (NOTE 2) of the serum under test into a row of circle on the card. When testing for Brucella antibodies 20ml is sufficient (NOTE 1). Dispense 1 drop of positive control serum and 1 drop of negative control serum into two additional circles.
- Add 1 drop of the appropriate well shaken suspension to each circle next to the sample to be tested.
- Mix the content of each circle with a disposable stirrer and spread over the entire area enclosed by the ring.
- Rock the slide gently by hand or means of a mechanical rotator (100 r.p.m) for a period of 1 minute.
- Observe immediately under a suitable light source for degree of agglutination.
RESULT Non reactive smooth suspension with no visible agglutination as shown by negative control.
Reactive Any degree of agglutination visible under microscope.
1 Semi Quantitative Test
- For each specimen to be tested place 30,40,20,10 and 5 NL of serum into each of the circle a card.
- Test each dilution as describe in step 4 to 7 for the quantitative test (Note 3)
Result Same as quantitative test.
Positive and Negative serums as well as suspension control tubes should be run daily to check the operatincity of the system.
Expected Values- Salmonella and Brucella:
Tilters greater than 1/80 (somatic and brucella antigens) and 1/60 (flagella antigens) indicate recent infection.
A single positive result has less chemical significance than the demonstration of a rising or decreasing tilter between successive serum specimens taken days apart.
Febrile Antigen is a term which has been accepted generally as referring to bacteria suspension representative of a number of pathogenic micro-organisms to human involved in some bacterial infection (brucellosis, salmonellosis and certain Rickettsiosis) which are accompanied by a fever in the host. The best option to establish the etiology of an infectious disease is by isolation and identification of the causative agent.
However, culture technique may not be considered and the febrile serodiagnostic test is importance to detect the antibodies produced in the patient serum during the infection (Indirect Method of Diagnosis).
Testing febrile antigens has a high diagnostic value of their exclusion or detection can support or place doubt on a tentative diagnosis made on the basis of case history data and clinical findings.
- There is no a reference material for the sensitivity standardization of these reagent. For the reason, linear chemical adjust the sensitivity of their reagent against specific antisera
- Prozone effect: false negative result may be obtained with antis era containing a high liter of antibodies. A dilution of these antis era will give a positive result
- Result obtained with this reagent did not show significance differences when compared with reference reagent. Details of the comparison experiment are valuable
- Hemoglobin (< 10g/L) bilirubin (< 20 mg/dl), Lipemia (< 10 mg/c) and rheumatoid factors (< 300N/ml) do not interfere.
Limitation of Procedure
- Biological false negative reaction can occur early in disease and in cases of immunounres ponsiveness.
- False negative somatic (O) test may be given by typhoid patient which have been treated with antibodies
- False positive (cross reaction) may be found with some stain of vibrio (campylobacter), Pasteur Ella, proteus and Y. enterocolitica (serotype 9) as well as in patient vaccinated with V. cholerac.
Sources of Errors
- Antigen used beyond their expiring dates may give false negative reaction
- Bacteria contamination of antigens, specimen or saline solution as well as freezing of the suspension may lead to false position result.
Tuberculosis is spread primarily via air borne transmission of aerosolized droplets developed by coughing, sneezing and talking. The greatest risk of contamination is usually observe in the area of poor ventilation.
TB is the major cause of mobility and mortality resulting in the large number of death due to single infections agent.
Prevention can be achieve by timely diagnosis to control TB as it provide early initiation of therapy and limit further spread of infection.
Several diagnosis method has been employed for detection of TB, these include skin test, sputum smear and sputum culture. They require laboratory equipment for this test to be carried out.
Test for. Tuberculosis (TB)
Several test has been carried out for qualitative detection of Anti-TB antibodies. This include Dias pot TB (Tuberculosis rapid test device for whole blood/ serum or plasma), zainesing method for sputum staining for AFB (Acid fast basalute) bacteria etc.