Why the pre-incubation? - (Apr/06/2011 )

Hi,

These are some steps from an experiment I did, but there is one step in particular which I don't understand the goal.

Here are the steps :
1: 1900µL of natural substrate Casein (0.1%) with Tris-HCl buffer (0.2M pH=7.2) poured in 4 tubes
2: 1st incubation (pre-incubation) for 10min at 37°C
3: Add different volums of venom (of Cerastes cerastes) to each tube (0, 2.5, 5, 10 µL)
4: 2nd incubation 10min 37°C
etc ...

My question, why the first incubation (pre-incubation)?

Though I'm not a pharmacologist I guess it's for two reasons:
All samples should have the same temperature.
The experimental temperature should be similar to natural conditions (as it's a snake venom that is working against endothermic animals such as rodents).

You guessed right, thank you for confirming ^^

Ilham on Wed Apr 6 21:26:34 2011 said:

How do you know? You asked your teacher?
Just being curious.