A tube assembly system for sample collection, the system comprising: - a tube assembly, wherein the tube assembly comprises: ∘ a first tube having first and second ends (12, 15), the first end of the first tube having an opening therein; ∘ a second tube having a first end and a second end, the first end of the second tube being open and having a diameter greater than the diameter of the first end of the first tube; ∘ a securing mechanism operable to secure the first tube and the second tube such that the first end of the second tube extends beyond the first end of the first tube, with the first end of the first tube inside the first end of the second tube creating an interstitial space about the first tube at the first end of the second tube; and ∘ a seal, wherein when the seal is placed against the first end of the second tube to form a barrier, a biological sample can a) pass from the first end of the first tube by way of the interstitial space into the opening of the second end of the second tube, or b) pass from the second end of second tube by way of the interstitial space into the opening of the first end of the first tube; - a sample source fluidly coupled to the second end of the first tube; and - a collection mechanism comprising a collection medium, wherein the collection medium is capable of binding biological samples, and wherein the collection mechanism is positioned to receive a fluid from the tube assembly. - a tube assembly, wherein the tube assembly comprises: ∘ a first tube having first and second ends (12, 15), the first end of the first tube having an opening therein; ∘ a second tube having a first end and a second end, the first end of the second tube being open and having a diameter greater than the diameter of the first end of the first tube; ∘ a securing mechanism operable to secure the first tube and the second tube such that the first end of the second tube extends beyond the first end of the first tube, with the first end of the first tube inside the first end of the second tube creating an interstitial space about the first tube at the first end of the second tube; and ∘ a seal, wherein when the seal is placed against the first end of the second tube to form a barrier, a biological sample can a) pass from the first end of the first tube by way of the interstitial space into the opening of the second end of the second tube, or b) pass from the second end of second tube by way of the interstitial space into the opening of the first end of the first tube; ∘ a first tube having first and second ends (12, 15), the first end of the first tube having an opening therein; ∘ a second tube having a first end and a second end, the first end of the second tube being open and having a diameter greater than the diameter of the first end of the first tube; ∘ a securing mechanism operable to secure the first tube and the second tube such that the first end of the second tube extends beyond the first end of the first tube, with the first end of the first tube inside the first end of the second tube creating an interstitial space about the first tube at the first end of the second tube; and ∘ a seal, wherein when the seal is placed against the first end of the second tube to form a barrier, a biological sample can a) pass from the first end of the first tube by way of the interstitial space into the opening of the second end of the second tube, or b) pass from the second end of second tube by way of the interstitial space into the opening of the first end of the first tube; a) pass from the first end of the first tube by way of the interstitial space into the opening of the second end of the second tube, or b) pass from the second end of second tube by way of the interstitial space into the opening of the first end of the first tube; - a sample source fluidly coupled to the second end of the first tube; and - a collection mechanism comprising a collection medium, wherein the collection medium is capable of binding biological samples, and wherein the collection mechanism is positioned to receive a fluid from the tube assembly.