Devices for collecting biological samples

A method, comprising

• obtaining a device, comprising:
• (a) one or more piercing elements configured to penetrate skin of a subject to expose blood;
• (b) a plunger configured to drive the one or more piercing elements into the skin of the subject;
• and
• (c) a removable collection chamber for collecting the blood;
• applying the device to the skin of the subject;
• actuating the plunger to cause the one or more piercing elements to pierce the skin of the subject;
• creating a vacuum upon withdrawal of the one or more piercing elements from the skin;
• and
• collecting greater than 100 μL of the blood in the removable collection chamber, wherein the removable collection chamber is configured to be removed from the device after the blood is collected in the removable collection chamber.