Method for flow mass spectrometry analysis

Abstract

This invention provides a flow cytometry mass spectrometry analysis method, comprising the following steps: (A1) labeling cells with a metal element and selecting a nuclide based on the metal element; adding the nuclide when preparing the cell solution; (A2) ionizing the metal element and the nuclide respectively and sending them to a time-of-flight mass spectrometer; (A3) the time-of-flight mass spectrometer outputs a first type of information on the change of the metal element intensity over time and a second type of information on the change of the nuclide intensity over time, compressing the second type of information over time to obtain the rate of change of the second type of information after compression in adjacent time periods; (A4) determining whether the rate of change exceeds a threshold; if it exceeds the threshold, the detection data of the metal element and nuclide corresponding to the adjacent time period are invalid; if it does not exceed the threshold, the detection data of the metal element and nuclide corresponding to the adjacent time period are valid. This invention has the advantages of low cost and high precision.

Description

Technical Field

[0001] This invention relates to mass spectrometry technology, and particularly to flow cytometry mass spectrometry analysis methods. Background Technology

[0002] In mass cytometry, the measurement of cells is often accompanied by organic contamination of the conical nozzle and interference from environmental fluctuations on the long-term stability of the instrument. In practical applications, a set of samples usually needs to be measured continuously for several hours. How to reduce the fluctuations in instrument performance caused by the above-mentioned external factors has become an important issue for the instrument's ultimate application.

[0003] Improving the long-term stability of instruments is a direct approach, but its development cycle is long and the return on investment is low. Therefore, while improving the physical limits of instruments, the mainstream approach in the market is to use standardized magnetic beads for calibration. This introduces a new variable, namely the consistency of magnetic beads, which not only places great demands on the preparation of magnetic beads, but also places higher requirements on users regarding the storage, transport, and proportioning of magnetic beads. Moreover, standardized magnetic beads are expensive, and a certain number of magnetic beads are required for each cell measurement, greatly increasing the cost of sample measurement. Summary of the Invention

[0004] To address the shortcomings of the existing technical solutions, this invention provides a flow cytometry mass spectrometry analysis method.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] Flow cytometry mass spectrometry analysis method, the flow cytometry mass spectrometry analysis method includes the following steps:

[0007] (A1) Label cells with metal elements and select nuclides based on the metal elements;

[0008] The aforementioned nuclide is added when preparing the cell solution;

[0009] (A2) The metal elements and nuclides are ionized and sent to a time-of-flight mass spectrometer;

[0010] (A3) The time-of-flight mass spectrometer outputs the first type of information on the change of the intensity of the metal element over time, and the second type of information on the change of the intensity of the nuclide over time. The second type of information is compressed over time to obtain the rate of change of the second type of information after compression in adjacent time periods.

[0011] (A4) Determine whether the rate of change exceeds the threshold;

[0012] If the threshold is exceeded, the detection data of metal elements and nuclides corresponding to the adjacent time period are invalid;

[0013] If the threshold is not exceeded, the detection data of metal elements and nuclides corresponding to the adjacent time period are valid.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. Low testing cost;

[0016] The elimination of magnetic beads significantly reduces costs;

[0017] 2. High analytical accuracy;

[0018] The prepared solutions have absolute consistency, thereby improving measurement accuracy;

[0019] The validity of detection data is confirmed by using changes in the intensity of nuclides, and the rate of change in nuclide intensity is used to correct for changes in the intensity of metallic elements, thus improving the accuracy of the analysis. Attached Figure Description

[0020] The disclosure of this invention will become more readily understood with reference to the accompanying drawings. It will be readily understood by those skilled in the art that these drawings are merely illustrative of the technical solutions of this invention and are not intended to limit the scope of protection of this invention. In the drawings:

[0021] Figure 1 This is a schematic flowchart of the flow cytometry mass spectrometry analysis method according to Embodiment 1 of the present invention. Detailed Implementation

[0022] Figure 1 The following description illustrates optional embodiments of the invention to teach those skilled in the art how to implement and reproduce the invention. Some conventional aspects have been simplified or omitted to explain the technical solutions of the invention. Those skilled in the art should understand that variations or substitutions derived from these embodiments will be within the scope of the invention. Those skilled in the art should understand that the following features can be combined in various ways to form multiple variations of the invention. Therefore, the invention is not limited to the following optional embodiments, but is defined only by the claims and their equivalents.

[0023] Example 1:

[0024] Figure 1 A flowchart illustrating the flow cytometry-mass spectrometry analysis method of an embodiment of the present invention is shown below. Figure 1 As shown, the flow cytometry mass spectrometry analysis method includes the following steps:

[0025] (A1) Cells are labeled using a metal element, the labeling method being existing in the art, and the nuclide is selected according to the metal element;

[0026] When preparing the cell solution, the aforementioned radionuclide is added, such as... 140 Ce、 151 Eu、 153 Eu、 165Ho、 175 Lu;

[0027] (A2) The metal elements and nuclides are ionized and sent to a time-of-flight mass spectrometer;

[0028] (A3) The time-of-flight mass spectrometer outputs the first type of information on the change of the intensity of the metal element over time, and the second type of information on the change of the intensity of the nuclide over time. The second type of information is compressed over time to obtain the rate of change of the second type of information after compression in adjacent time periods.

[0029] (A4) Determine whether the rate of change exceeds the threshold;

[0030] If the threshold is exceeded, the detection data of metal elements and nuclides corresponding to the adjacent time period are invalid;

[0031] If the threshold is not exceeded, the detection data of metal elements and nuclides corresponding to the adjacent time period are valid.

[0032] To correct the intensity of metallic elements and improve analytical accuracy, the flow cytometry-mass spectrometry method further includes the following steps:

[0033] (A5) The rate of change of the second type of information after compression in the effective data of the nuclide;

[0034] (A6) Correct the first type of information based on the rate of change.

[0035] To monitor whether the solution preparation is incorrect, further, in step (A4), if the detection data of most nuclides are invalid, it indicates that the cell solution preparation is incorrect.

[0036] To further reduce the amount of data processing, the compression method is as follows:

[0037] The information is divided into equal-length time periods to obtain the sum or average value of the kernel intensity in each time period.

[0038] To improve the accuracy of the analysis, further, in step (A6), the correction method is as follows:

[0039] The corrected strength of a metallic element is A = A0(1-K), where A0 is the original strength and K is the rate of change.

[0040] To further improve analytical accuracy, nuclides are selected based on the range of their mass numbers and their proximity to the mass numbers of metallic elements.

[0041] Example 2:

[0042] An application example of the flow cytometry mass spectrometry analysis method according to Embodiment 1 of the present invention.

[0043] In this application example, such as Figure 1 As shown, the flow cytometry mass spectrometry analysis method includes the following steps:

[0044] (A1) Cells are labeled using metal elements, and the labeling method is a prior art in this field;

[0045] Nuclide selection is based on the range of mass numbers and their proximity to the mass numbers of metallic elements. In this embodiment, the selected nuclide is... 140 Ce、 151 Eu、 153 Eu、 165 Ho、 175 Lu;

[0046] When preparing the cell solution, add the selected nuclide;

[0047] (A2) The metal elements and nuclides are ionized and sent to a time-of-flight mass spectrometer;

[0048] (A3) The time-of-flight mass spectrometer outputs first-type information on the change of the intensity of the metallic element over time, and second-type information on the change of the intensity of the nuclide over time.

[0049] The second type of information is divided into equal-length time periods, and the sum or average value of the kernel intensity in each time period is obtained. This compresses the second type of information in time and obtains the rate of change of the second type of information after compression between adjacent time periods, that is, the rate of change of intensity.

[0050] (A4) Determine whether the rate of change exceeds the threshold;

[0051] If the threshold is exceeded, the detection data of metal elements and nuclides corresponding to the adjacent time period are invalid;

[0052] If the threshold is not exceeded, the detection data of metal elements and nuclides corresponding to the adjacent time period are valid;

[0053] If the detection data for most nuclides are invalid, such as three or four out of five nuclides, it indicates that the cell solution is incorrectly prepared.

[0054] (A5) The rate of change of the second type of information after compression in the effective data of the nuclide;

[0055] (A6) Correct the first type of information based on the rate of change, wherein the correction method is as follows:

[0056] The corrected strength of a metallic element is A = A0(1-K), where Ax is the original strength and K is the rate of change.

Claims

1. A flow cytometry-mass spectrometry analysis method that does not require the use of magnetic beads, the flow cytometry-mass spectrometry analysis method comprising the following steps: (A1) Label cells with metal elements and select nuclides based on the metal elements; The aforementioned nuclide is added when preparing the cell solution; (A2) The metal elements and nuclides are ionized and sent to a time-of-flight mass spectrometer; (A3) The time-of-flight mass spectrometer outputs the first type of information on the change of the intensity of the metal element over time, and the second type of information on the change of the intensity of the nuclide over time. The second type of information is compressed in time to obtain the rate of change of the second type of information after compression in adjacent time periods. (A4) Determine whether the rate of change exceeds the threshold; If the threshold is exceeded, the detection data of metal elements and nuclides corresponding to the adjacent time period are invalid; If the threshold is not exceeded, the detection data of metal elements and nuclides corresponding to the adjacent time period are valid; (A5) The rate of change of the second type of information after compression in the effective data of the nuclide; (A6) Correct the first type of information based on the rate of change; The corrected strength of a metallic element is A = A0(1-K), where A0 is the original strength and K is the rate of change.

2. The flow cytometry-mass spectrometry analysis method according to claim 1, characterized in that, In step (A4), if the detection data for most nuclides are invalid, it indicates that the cell solution is incorrectly prepared.

3. The flow cytometry-mass spectrometry analysis method according to claim 1, characterized in that, The compression method is as follows: The information is divided into equal-length time periods to obtain the sum or average value of the kernel intensity in each time period.

4. The flow cytometry-mass spectrometry analysis method according to claim 1, characterized in that, Nuclide selection is based on the range of its mass number and its proximity to the mass number of metallic elements.

5. The flow cytometry-mass spectrometry analysis method according to claim 4, characterized in that, The nuclide is 140 Ce、 151 Eu、 153 Eu、 165 Ho、 175 Lu.

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