Science Buddies: "Ask an Expert"

Hello Im currently doing a science project for my science class im and getting my idead from this site: https://www.sciencebuddies.org/science- ... ml#summary

Im trying to make it a little bit different by testing the affects the amounts of platelets would have on blood coagulation. I want to ask if i can still use the same materials and the same procedure for this. Any help would be wonderful and in addition to this project i have to make a community connection. This means that I have to find a way that my project can somehow relate to my community. I currently don't really have any idea on this so if anyone can give me some ideas that would be really helpful.

Hi frostywing,

It sounds like you want to test the differences in clotting when platelets are available in different amounts. So in this experiment, the calcium chloride solution is mimicing the platelets (because both provide calcium to the chemical reaction). If you wan to increase your "platelets" could you simply increase the concentration of the calcium chloride solution? What would you expect to happen? Will further increases cause further changes in the results? Does this help get you started?

The community connection - I thnk the background section explains this pretty well - blood clotting is important anytime someone is injured and bleeding. Without clotting we would bleed completely out and die.

Tonya

Good luck on your project!

So if im not doing anything with coagulants then i would be using the Sodium Citrate then?

You will still use the "coagulants" (sodium citrate) so you can test the effect of platelet concentration changes. It sounds like you will run the experiment as it is shown, but do it numerous times, varying the amount of platelets present.

What should i do for the control then? I also want to ask what increment of Calcium Chloride I should use for measurable results?

-Thank You so much for the help you have given me!

Frostywing wrote:What should i do for the control then? I also want to ask what increment of Calcium Chloride I should use for measurable results?

-Thank You so much for the help you have given me!

Hi again,
To start with make sure this section of the Project Guide is clear to you. Actually, you may be able to pick out the controls more easily after reviewing this:
https://www.sciencebuddies.org/science- ... bles.shtml

Hint - you are changing the CaCl concentration, so another part of the experiment must be controlled instead...

Re: the CaCl concentration - this is where trial and error, or "pilot experiments" come in. You can make an educated guess going slightly under and above the concentration given in the procedure. Maybe even FAR over or under the concentration given, so as to have the largest spread of data. If you have the ability, you could do a test run to see if the concentrations you picked actually do cover the range you need to see your expected results (based on your hypothesis).

Did this make sense and get you going again? If not, let me know, I can definatley be more specific, BUT you are doing pretty good developing this procedure on your own

Tonya

So i have figured out what im going to and can you tell me if this could work? The control would be 6 grams of each ingredient. The increment for the platelets would be 4 grams. Would that work out well?

-Thanks

Hi again,

Let me work through this with you.

You wil need to select a sodium citrate concentration to use and keep constant. It looks like (from the procedure) - no sodium citrate will always cause coagulation (because there is no inhibitor present in the reaction). You could use 1% sodium citrate (balls will form in some conditions), and vary the cacl (platelets) to find the value of cacl that overcomes the inhibition from the sodium citrate.

The chart in step 2 would look the same, except the variable on the right side would be the concentrations of cacl you used, keeping the sodium citrate at 1%.

Step 4d - you want to vary the amount of calcium you use, so maybe make one with 0, one with 1.3g (as described). What results do you expect here? No calcium should give no ball formation (no coaggulation). 1.3g should give coagulation... so the variations in cacl concentration should take place between these two concentrations. Maybe use 0.2g increments? and go beyond the 1.3g to be sure?

So the expected results would look like this in the chart for step 2:

Sodium citrate always at 1% (coaggulation can occur if cacl present).
Cacl used: 0, 0.2g, 0.4g, 0.6g, 0.8g, 1.0g, 1.2g, 1.4g, 1.6g
Ball formation (going across the Cacl amounts above): You will measure and find out. I expect no calcium gives no ball formation. More cacl eventually gives ball formation.

Does that help?

Good luck!