The Multi Crystal LB 2111 gamma counter from BERTHOLD TECHNOLOGIES is a compact, robust and easy-to-use instrument for most applications where gamma-emitting isotopes are used. The instrument can be operated in a stand alone mode or can be hooked to a personal computer. In either of the options the user is guided through a clearly structured and easy-to-use assay setup. Templates facilitate the definition of new measurement protocols and data evaluation. Sample loading is made easy and convenient by means of 12 position sample racks that are simply inserted into the matching boreholes of the detector crystals. Sample throughput is high as 12 tubes (or even 24 tubes with the extended model) can be measured at a time. The absence of any moving parts and the robust electronics guarantee a long lifetime and error-free operation.

Sample Racks

The sample racks facilitate loading of 12 samples at a time in a most convenient way. With multiple racks all samples of a measurement campaign can be prepared in advance. The sample rack concept has another important advantage: in case a tube is contaminated on the outside the contamination is never carried on to the instrument. The racks themselves can be cleaned and decontaminated.

Detectors

The 12 detectors are made of high-quality NaI borehole “well type” crystal providing best measurement geometry for -emitters located in a sample tube. The crystals cover an energy range up to 500 KeV - suitable for the common isotopes,e.g. 125I, 57Co, 59Fe, 51Cr and 99Tc. A thick lead shield of 6 mm, i.e. in total 12 mm of lead surrounding each of the detectors efficiently prevents crosstalk between the samples in the individual detectors. For specific loading patterns any of the detectors can be disabled individually. Exchangeable plastic liners prevent detector contamination.

Detector standardisation

The standardisation procedure corrects for slight variations in detector efficiencies. Either, a single tube containing the isotope e.g. 125I, is sequentially counted in each of the detectors or 12 tubes, each with the same amount of activity, are counted simultaneously in all 12 detectors. Together with the standardisation the high voltage supply is optimised for each detector.

Instrument models

The Multi Crystal LB 2111 gamma counter is available as a 12 detector unit. To increase throughput a second detector block may be added resulting in a 24 detector instrument. Both models can be operated stand alone or with the PC software LBIS.

Stand alone operation

In this configuration a video terminal and a keyboard are connected to the gamma counter. A serial matrix printer is to be used for data output. The stand alone configuration supports all requirements of a laboratory’s routine assays incl. raw data (CPM), RIA, IRMA, ratio and receptor type.

LBIS immunoassay evaluation software

The LBIS software is a Windows based instrument operation and data evaluation software with a graphical user interface. It supports all common types of competitive (RIA) and immunometric (IRMA) assays with superior curve fitting algorithms increasing the reliability of the calculated results at the lower concentrations. LBIS supports worklist download and sample data upload to host computers. Up to 4 instruments connected to one PC can be run with one LBIS