In the clinical laboratory, inspectors often observe an interesting phenomenon: when opening a blood collection tube with a red or yellow cap and carefully examining it under light, a faint misty film appears on the inner wall of the test tube. This seemingly ordinary phenomenon contains important quality information about the coagulant process behind it. This article will delve into the causes and clinical significance of the phenomenon of "fogging" on the inner wall of blood collection vessels.

blood coagulants

1、 The cause of misty film: a natural result of coagulant spraying process

The application of coagulants in blood collection tubes is a precise process. During the production process, it is necessary to first prepare coagulant powder (such as diatomaceous earth, kaolin, etc.) into a uniform suspension, and then evenly apply it to the inner wall of the test tube through precision spraying equipment. In the subsequent drying process, after the liquid carrier evaporates, the solid particles of the coagulant adhere to the pipe wall in the form of a thin film, forming the "misty" appearance we observe. This misty membrane is essentially the uniform distribution of fine solid particles on the inner wall of the test tube, and is an important visual indicator for the successful application of coagulants, proving that coagulants have been evenly distributed on the inner surface of the blood collection tube.

2、 Particle size difference: a key factor in the degree of "fog like" visibility

The particle size distribution of different coagulant raw materials is the primary factor affecting the degree of "fogging". When using smaller particle size coagulant materials (such as nanoscale silica), the formed film is denser and has weaker scattering of light, so the "foggy" effect observed by the naked eye is not obvious and requires a specific angle to detect. In contrast, when using larger particle size coagulant materials (such as micron sized kaolin), the particles have a stronger scattering effect on light, and the formed film is more visually apparent. This difference is mainly determined by the physical properties of the material and is not directly equivalent to the quality of the product.

3、 Process control: key technology to ensure uniformity of mist film

The uniformity of the misty film is an important indicator for evaluating the quality of the coagulant spraying process. The ideal coagulant film should present a uniform misty appearance without obvious stripes, spots, or clusters. This uniformity depends on precise control of multiple process parameters: spray pressure affects droplet atomization effect, tube rotation speed affects coating uniformity, and drying temperature curve directly affects the distribution morphology of solid particles. Modern advanced production processes use automated control systems to ensure consistent application of coagulants to each blood collection tube.

4、 Quality assessment: How to evaluate the quality of coagulants through visual inspection

The "foggy" appearance provides an intuitive preliminary judgment basis for quality control. A qualified coagulant film should have the following characteristics: overall uniformity, no visible particle aggregation; Maintain consistent visual characteristics between blood collection tubes from different batches; However, it should be emphasized that visual inspection is only a preliminary judgment. A more accurate quality assessment relies on laboratory testing methods, including coagulation performance testing, coagulation time determination, serum quality assessment, etc. Legitimate coagulant manufacturers will conduct strict full performance testing on each batch of products to ensure that their quality meets relevant standards.

Product packaging

Hubei Xindesheng Material Technology Co., Ltd. has been deeply engaged in the field of in vitro diagnostic raw materials for more than 20 years. It has a profound technical accumulation and rich practical experience in the field of blood collection tube additives, especially in the research and production of blood coagulants. It has achieved very good results. If you need it, please feel free to come to the factory for inspection.