Cover Image
close this bookHealth Laboratory Facilities in Emergencies and Disaster Situations. (WHO - OMS, 1994, 169 p.)
close this folderAnnexes
View the documentAnnex 1. Agencies providing health relief
View the documentAnnex 2. Reference laboratories for communicable diseases
View the documentAnnex 3. Manufacturers of portable or mobile laboratories
View the documentAnnex 4. Commercially available rapid diagnostic kits and reagents and their manufacturers
View the documentAnnex 5. Reagents for urinalysis
View the documentAnnex 6. Manufacturers of water testing kits
View the documentAnnex 7 Collecting water samples for microbiological examination
View the documentAnnex 8 Non-profit-making suppliers for tropical laboratories
View the documentAnnex 9 Manufactures of photovoltaic equipment
View the documentAnnex 10 Manufacturers of microscopes
View the documentAnnex 11 Manufacturers of battery-driven and mechanical laboratory centrifuges
View the documentAnnex 12 Manufacturers of portable colorimeters and haemoglobinometers
View the documentAnnex 13 Suppliers of portable incubators discussed in the guidelines
View the documentAnnex 14 Cold chain equipment for blood storage and transport
View the documentAnnex 15 Manufacturers of photovoltaic refrigerators
View the documentAnnex 16 Manufacturers of water purification systems
View the documentAnnex 17 Filter paper technique for collection and transport of body fluid specimens

Annex 17 Filter paper technique for collection and transport of body fluid specimens

General

The transport of liquid specimens soaked on filter paper is a simple and safe procedure. The filter paper can be used in any format but is commonly incorporated into a form or card specifically constructed for sample collection. All kinds of body fluids can be absorbed, although the technique is most often used for the collection of blood. The card can be easily transferred to a distant laboratory for screening or confirmatory testing. Body fluid absorbed on a filter paper can be processed for qualitative and/or quantitative serological and immunological investigations. Suitable filter paper is Whatman no. 1 or Schleicher and Schuell1. Cards with incorporated filter paper, which can also be used for registration of the patient and filing, can be obtained from Schleicher and Schuell.

1 Schleicher and Schuell GmbH, P.O. Box 4, D-3354 Dassel, Germany.
Tel: (0049)55612-791-0; Fax (0049)5561-791536

Technique for blood sampling

1.

The wearing of gloves is recommended for blood sampling. It is important that the filter paper surface does not come into contact with gloved hands or any other material, solutions and lotions, prior to and during the entire process of sampling.



2.

Complete the patient’s data on the card with a ball-point pen. Do not touch the filter paper circle area.



3.

Clean the puncture site on the patient’s finger tip, or heel if an infant, with 70 % alcohol. Wipe the site dry with a sterile gauze. Use a sterile disposable lancet for puncture. Wipe away the first drop of blood with dry sterile gauze.



4.

Gently touch the filter paper against a large drop of blood and allow the blood to soak through, until the preprinted circle on the filter paper is completely filled. Avoid squeezing the punctured site as this will cause haemolysis of the specimen and a dilution of the blood with tissue fluids. Do not layer successive drops of blood in the printed circle because this may cause caking. Do not apply blood to the filter paper more than once. Apply blood to one side of the filter paper only. Incompletely blood-soaked circles are not acceptable



5.

Allow the blood specimen to dry for 3 hours in the air in a horizontal and preferably elevated position (to avoid contamination and to allow better circulation of the air around the card for drying). Do not let the specimen come into contact with any surface, direct heat or sunlight. Do not refrigerate the samples.



6.

Place each dry specimen card into an envelope or a small plastic bag, add a few granules of desiccant and close the envelope hermetically for mailing. Store the filter paper in a plastic bag in a cool dark dry place. Specimens that have been stored up to three months, under appropriate conditions, may give acceptable results.


Figure A.1 Blood sampling on filter paper