A magnetic separating device for isolating magnetically labelled particles from a non-magnetic medium comprising: a body portion having a magnetising portion for providing a magnetic field and a surface by means of which the body portion may stand on a supporting surface; and a sample vessel retaining portion for retaining at least one sample vessel, the at least one sample vessel comprising a main volume region and a tip region, wherein, the magnetising portion is configured to conform to at least a portion of the longitudinal profile of the at least one sample vessel, the magnetising portion comprising an external wall, whereby when the sample vessel retaining portion receives the magnetising portion, an internal wall of the sample vessel retaining portion is in juxtaposition with the external wall of the magnetising portion, wherein (i), when the magnetising portion is closed cylinder-like, the internal wall of an open cylinder-like sample vessel retaining portion is located in juxtaposition with a side wall of the closed cylinder-like magnetising portion, or (ii), when the magnetising portion is arranged between feet members (140a, 140b), the internal wall of the sample vessel retaining portion is located in juxtaposition with outer walls of the feet members (140a, 140b) and an upper surface of the magnetising portion; the external wall of the magnetising portion comprising an upper wall portion that is substantially vertical and a lower wall portion that is inclined with respect to the upper wall portion, the upper wall portion conforming to the profile of the main volume region of the at least one sample vessel and the lower wall portion conforming to the profile of the tip region of the at least one sample vessel; the sample vessel retaining portion is configured to retain the at least one sample vessel such that at least a portion of the contents of the sample vessel is visible to a user; the sample vessel retaining portion is configured to be mountable on the magnetising portion so that in use, the at least one sample vessel is subject to the magnetic field of the magnetising portion and the at least one sample vessel is arranged in confronting relation to (i) the side-wall of the closed cylinder-like magnetising portion when the magnetising portion is closed cylinder-like or (ii) one side-wall of the external wall of the magnetising portion when the magnetising portion is arranged between the feet members (140a, 140b); and the magnetising portion further comprising at least one magnet which is shaped and arranged such that the main volume region and the tip region of the at least one sample vessel are subject to a high-gradient magnetic field. a body portion having a magnetising portion for providing a magnetic field and a surface by means of which the body portion may stand on a supporting surface; and a sample vessel retaining portion for retaining at least one sample vessel, the at least one sample vessel comprising a main volume region and a tip region, wherein, the magnetising portion is configured to conform to at least a portion of the longitudinal profile of the at least one sample vessel, the magnetising portion comprising an external wall, whereby when the sample vessel retaining portion receives the magnetising portion, an internal wall of the sample vessel retaining portion is in juxtaposition with the external wall of the magnetising portion, wherein (i), when the magnetising portion is closed cylinder-like, the internal wall of an open cylinder-like sample vessel retaining portion is located in juxtaposition with a side wall of the closed cylinder-like magnetising portion, or (ii), when the magnetising portion is arranged between feet members (140a, 140b), the internal wall of the sample vessel retaining portion is located in juxtaposition with outer walls of the feet members (140a, 140b) and an upper surface of the magnetising portion; the external wall of the magnetising portion comprising an upper wall portion that is substantially vertical and a lower wall portion that is inclined with respect to the upper wall portion, the upper wall portion conforming to the profile of the main volume region of the at least one sample vessel and the lower wall portion conforming to the profile of the tip region of the at least one sample vessel; the sample vessel retaining portion is configured to retain the at least one sample vessel such that at least a portion of the contents of the sample vessel is visible to a user; the sample vessel retaining portion is configured to be mountable on the magnetising portion so that in use, the at least one sample vessel is subject to the magnetic field of the magnetising portion and the at least one sample vessel is arranged in confronting relation to (i) the side-wall of the closed cylinder-like magnetising portion when the magnetising portion is closed cylinder-like or (ii) one side-wall of the external wall of the magnetising portion when the magnetising portion is arranged between the feet members (140a, 140b); and the magnetising portion further comprising at least one magnet which is shaped and arranged such that the main volume region and the tip region of the at least one sample vessel are subject to a high-gradient magnetic field.