The group loved this activity - it proved highly entertaining and simple to carry out for non-specialist teachers. Plenty of the synthetic blood and pseudo-antibody serum is provided, so although it says enough for one class, in fact you may have enough for two. There is a very detailed and informative booklet with a scenario to investigate, and photocopiable student sheets. There are also 'blood typing cards', which are just laminated cards with circles printed on them, labelled with Anti-A, Anti-B, and Anti-D. You put a glass slide over the card and add one drop of synthetic blood to each field, and one drop of the synthetic antibody serum. The mixing takes place on the slide and the card is just there to help the student keep track of what is being mixed in each field. However, only one set of laminated cards and blank glass slides is provided - ie enough for one small group of 1-4 people. This isn't really a problem but if you want a whole class to do this together then you will need to provide spotting tiles or lots of blank glass slides to enable them to do so. I made extra cards to go under the slides as it was useful to have this.
The booklet suggests various activities - looking at the inheritance of blood groups,and blood donor compatibility. The scenario posited in the booklet is a baby with disputed paternity. It had my group in stitches - Mary's estranged husband, John, is not sure that he is the father of baby Matthew as she has been spending a lot of time with her close friend, David, of late! If this scenario seems inappropriate for your group then I'm sure it could be rephrased somehow! The photocopiable student handouts don't include the scenario - they just tell students how to carry out the tests and include a table for results for each named individual.
The accompanying booklet is very clear and has plenty of background information and suggestions for extension activities and additional work, eg on Rhesus babies. Several lessons' worth in here.