ffutures | Fake Blood Typing

Ages ago I was looking for a way to fake blood typing on the cheap, and nobody could give me a recipe.

I've finally found something that works; in the unlikely event that anyone else happens to need to do this experiment, here's the method etc. What I've done is print the method (not the technician / teacher bit) onto laminated cards with a space marked for a microscope slide with two black areas underneath it - you could do it on a black spotting tile instead, of course.

Blood Grouping Test
For safety reasons this test uses chemicals to simulate blood and antigens. The chemicals are irritant or harmful; please handle with care. This experiment will not work properly if any of the chemicals are contaminated!

1. Put a microscope slide on the outline below so that it covers the two black squares
2. Put one drop of Antibody A solution onto the slide above the left-hand square.
Keep the pipette with the bottle of solution.
3. Using another pipette, put one drop of Antibody B solution onto the slide above the right-hand square.
Keep the pipette with the bottle of solution.
4. Put one drop of the blood you are testing onto each drop of antibody – make sure that the pipette does not touch anything on the slide.
Keep the pipette with the blood sample.
5. Look at the slide
• If the Antibody A square has a white precipitate but the other square is clear the blood is GROUP A
• If the Antibody B square has a white precipitate but the other square is clear the blood is GROUP B
• If BOTH squares have a white precipitate the blood responds to A and B antibodies and is GROUP AB
• If NEITHER square has a precipitate the blood doesn't respond to either antibody and it is GROUP O

Technical notes – Teacher / Technician only

Solutions are as follows

A - 0.5M Sodium Chloride + red food dye
B - 0.1M Barium Nitrate + red food dye - Irritant
AB - A 50/50 mix of the above
O - Distilled water + red food dye
Antibody A - 0.1M Silver Nitrate - Irritant, Oxidizer
Antibody B - 5% Sodium silicate solution - Irritant

The precipitate produced is white so doesn’t look much like clumping cells, but this gives an impression of how the real test works.

later Needless to say I spotted three errors AFTER laminating the cards...