†No purchase necessary. This promotion is available only to life science professionals in the US (excluding Puerto Rico) and Canada who are 21 years or older. Sample requests must be received by October 15, 2018, or before sample supplies are depleted, whichever comes first. The sample size is 1 L. Limit one free sample. Cannot be combined with other discounts or promotions. Offer void where prohibited, licensed, or restricted by federal, state,provincial, or local laws or regulation or agency/institutional policy. Other restrictions may apply.