Needle assembly (10) for collecting blood or other liquid samples for discharge into a container, the needle assembly (10) comprising: a housing (12), a first needle hub (18) provided by said housing (12), a first hollow needle (20) portion mounted to said first needle hub (18) and extending from said first needle hub (18) in a distal direction, the first needle (20) having a sharpened first needle tip (22), a second needle hub (30) provided by said housing (12), a second hollow needle (32) portion mounted to said second needle hub (30) and extending from said second needle hub (30) in a proximal direction, opposite to said distal direction, wherein a hollow flashback chamber is arranged within the housing between the first needle (20) portion and the second needle (32) portion, wherein the flashback chamber communicates with the inner lumen provided within the first (20) and second (32) hollow needle portion, wherein the housing (12) is formed from transparent material at least in a region close to the flashback chamber, wherein the flashback chamber is connected to the atmosphere by a passage and wherein a filter (94) is provided within the passage, wherein the filter (94) is designed such that it is permeable for air to pour out of the flashback chamber into the atmosphere but prevents blood or other liquid samples contained in the flashback chamber from pouring out through an opening into the atmosphere.
