While growing my bacterial culture in liquid media for protein expression, I noticed that the E. coli cells initially grow well until the OD600 reaches approximately 0.4-0.6, after which they abruptly disappear. The previously turbid culture becomes clear, and there is no significant cell debris precipitated. However, some particles are present, making the media appear hazy, suggesting cell lysis. Despite altering media components, resources, temperature, cell lines, and genes of interest, the issue persists. The occurrence is random and lacks a discernible pattern. Any advice on potential causes or similar experiences would be greatly appreciated. Thank you.