A system for detection and screening of umbilical cord blood stem cells

Abstract

The present application relates to the technical field of genome sequencing, in particular to a detection and screening system for umbilical cord blood stem cells, which comprises a collection and processing unit, a detection and analysis unit and a judgment output unit, the present application obtains umbilical cord blood samples by sampling umbilical cord blood, and obtains umbilical cord blood stem cells through automatic processing, uses high-throughput sequencing technology to sequence the gene fragments of the umbilical cord blood stem cells, determines the sequencing depth and coverage of the gene fragments of the umbilical cord blood stem cells, improves the accuracy of detection, reduces the false negative rate, and ensures that more comprehensive genomic regions are analyzed, automatically analyzes the gene fragments of the umbilical cord blood stem cells according to the sequencing depth and coverage, obtains a comparison quality score, and judges whether the gene fragments of the umbilical cord blood stem cells have mutations according to the comparison quality score, and uploads the judgment result to a user interface.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of genome sequencing technology, in particular, to a detection and screening system for umbilical cord blood stem cells. BACKGROUND

[0002] Genome sequencing is an important technology, modern genome sequencing technology can simultaneously sequence a large number of DNA fragments, greatly improving the experimental efficiency, reducing the time and cost, stem cells (Stem Cells, SC) are a kind of self-renewing pluripotent cells, which are primitive and unspecialized cells, which can differentiate into various functional cells under certain conditions, have the potential function of regenerating various tissues and organs and human body, stem cells exist in all multicellular tissues, can be divided into various specialized cells by mitosis and differentiation, and can provide more stem cells by self-renewal, the source of stem cells is many, including umbilical cord blood and bone marrow, for mammals, stem cells are divided into two categories: umbilical cord blood stem cells (Embryonic Stem Cell, ESC) and adult stem cells (Adult Stem Cell, ASC), umbilical cord blood stem cells are taken from the inner cell mass of blastocyst, and adult stem cells are from various tissues, umbilical cord blood stem cells have important medical value, but the existing detection and screening method has the problem of low efficiency when checking mutations of expected stem cells, in order to solve this technical problem, we provide a detection and screening system for umbilical cord blood stem cells. SUMMARY

[0003] The purpose of the present application is to provide a detection and screening system for umbilical cord blood stem cells to solve the problems raised in the background art.

[0004] To achieve the above purpose, a detection and screening system for umbilical cord blood stem cells is provided, which comprises a collection and processing unit, a detection and analysis unit, and a judgment and output unit.

[0005] The collection and processing unit is used for collecting, sub-packaging and sampling the umbilical cord blood contained in the umbilical cord to obtain umbilical cord blood samples, and pre-treating the umbilical cord blood samples by automatic processing to obtain umbilical cord blood stem cells.

[0006] The detection and analysis unit introduces high-throughput sequencing technology to divide the gene fragments of umbilical cord blood stem cells into multiple segments of equal length, simultaneously sequences the gene fragments of umbilical cord blood stem cells in multiple segments, and determines the sequencing depth and coverage of the gene fragments of umbilical cord blood stem cells.

[0007] The judgment output unit automatically analyzes the gene fragments of the cord blood stem cells according to the sequencing depth and coverage, obtains a comparison quality score, judges whether the gene fragments of the cord blood stem cells have mutations according to the comparison quality score, and uploads the judgment result to a user interface.

[0008] As a further improvement of the technical solution, the collection processing unit uses a four-in-one blood collection bag to collect the umbilical cord blood of a newborn in a closed manner, stores the collected umbilical cord blood according to different detection items, extracts samples from the separated umbilical cord blood, and pre-processes the umbilical cord blood samples through automatic processing to obtain cord blood stem cells.

[0009] As a further improvement of the technical solution, the pre-processing of the umbilical cord blood samples through automatic processing to obtain cord blood stem cells specifically includes:

[0010] The collected umbilical cord blood sample is placed in a cell separation machine based on the principle of centrifugation. After starting centrifugation, first start at a centrifugal speed of 500 rpm for two minutes to gradually adapt the sample to the centrifugal force, then gradually increase the speed to 1800 rpm for ten minutes to promote the effective stratification of different components in the umbilical cord blood. After the main centrifugation stage, the speed is gradually reduced by 200 rpm per minute until it stops to avoid damage to cells due to sudden stopping. The intermediate layer cell suspension of stem cells is automatically collected. The separated cell suspension is transferred to a cell purification kit. The reagents in the kit interact with the cells, specifically binding non-stem cell components, removing the combined impurities by filtration, and leaving pure cord blood stem cells.

[0011] As a further improvement of the technical solution, the detection and analysis unit introduces high-throughput sequencing technology to sequence the gene fragments of the cord blood stem cells, determines the sequencing depth and coverage of the gene fragments of the cord blood stem cells, and specifically includes:

[0012] High-throughput sequencers usually require specific library formats and fragment sizes for effective sequencing. Library construction fragments nucleic acids to appropriate lengths and adds necessary adapters and primer binding sites to make them compatible with sequencing platforms.

[0013] The nucleic acid is extracted from the cord blood stem cells, the extracted long-chain nucleic acid is randomly cut into fragments with k base pairs in length by ultrasonic fragmentation, the ends of the fragmented nucleic acid are smoothed by enzymes, a phosphate group is added to make the end structure complete, an oligonucleotide adapter is connected to the ends of the repaired nucleic acid fragments, the oligonucleotide adapter comprises a primer binding site and an index sequence required for sequencing, the library construction is completed, the constructed library is loaded onto a high-throughput sequencer for sequencing, the total sequencing base number of the cord blood stem cells is obtained, the genome size is determined according to the total sequencing base number of the cord blood stem cells, the sequencing depth and the coverage are calculated from the total sequencing base number and the genome size of the cord blood stem cells, the calculation of the sequencing depth and the coverage, the genome size is specifically calculated by the formula:

[0014] ;

[0015] wherein, is the genome size, is the frequency of k-mer with a specific length calculated by sequencing data statistics, is the total sequencing base number, is a correction factor, and the k-mer refers to a subsequence with a length of k base pairs continuously taken from a nucleic acid sequence.

[0016] As a further improvement of the technical solution, the calculation of the sequencing depth and the coverage specifically comprises:

[0017] The sequencing depth is used to increase the sensitivity of detection, by increasing the sequencing depth, i.e. sequencing a certain site more times, the probability of detecting low-frequency mutations can be increased, even if the proportion of mutations in the sample is very small, sufficient sequencing depth can provide more opportunities to find these rare mutation events, the coverage indicates that the genome is fully covered, so that most regions in the genome can be sequenced, the sequencing depth and the coverage are calculated from the total sequencing base number and the genome size of the cord blood stem cells, the calculation formula of the sequencing depth is:

[0018] ;

[0019] wherein, is the sequencing depth, is the total sequencing base number, is the genome size, and the calculation formula of the coverage is:

[0020] ;

[0021] wherein, ​This represents the coverage, and k represents the number of sequencing reads.

[0022] As a further improvement to this technical solution, the judgment output unit automatically analyzes the sequencing depth and coverage of gene fragments from umbilical cord blood stem cells to obtain an alignment quality score, specifically including:

[0023] The base quality value is extracted from the gene fragment of umbilical cord blood stem cells, and the formula for calculating the base quality value is as follows:

[0024] ;

[0025] in, This represents the probability that the base is misread during sequencing. The average base quality is set as the base quality threshold. Reads with quality values ​​below the threshold are deleted. Adapter sequences at both ends of the sequencing reads are identified and cut off, and duplicate reads are deleted to obtain the alignment sequence. An alignment algorithm is used to align the alignment sequence with a standard genome, which is extracted from a gene bank. The position of the read on the reference genome and the alignment quality score are recorded. The position is represented by coordinates on the genome, and the alignment quality score is used as a numerical indicator to evaluate the quality of the alignment between the read and the reference genome.

[0026] As a further improvement to this technical solution, the judgment output unit determines whether gene fragments of umbilical cord blood stem cells have mutated based on the comparison quality score, specifically including:

[0027] Sequencing data of umbilical cord blood stem cells were acquired, preprocessed, and aligned to obtain the alignment quality score of each read on the reference genome. By analyzing the alignment quality scores of a large number of known normal umbilical cord blood stem cell samples, a threshold was determined. For the umbilical cord blood stem cell gene fragment to be detected, the statistical value of the alignment quality scores of all reads contained therein was calculated. If the statistical value of the alignment quality score of the gene fragment is lower than the set threshold, the gene fragment is determined to have a mutation.

[0028] As a further improvement to this technical solution, if the alignment quality score of the gene fragment is lower than a set threshold, then the gene fragment is determined to have mutated, specifically including:

[0029] The standard genome sequence was defined as The alignment sequence is defined as Define a fractional function Indicates the first sequence in the alignment sequence The quality score of each position is calculated for each gene fragment position i, using the standard genome sequence. and alignment sequence Matching score :

[0030] ;

[0031] For insertion and deletion, define insertion penalty and deletion penalty If the sequencing sequence inserts a new base at position i, set the insertion penalty score as Then Otherwise If the sequencing sequence deletes a base at position i, set the deletion penalty score as Then Otherwise Combine the matching score, insertion penalty and deletion penalty to calculate the score of position i :

[0032] ;

[0033] Score all positions of the alignment sequence to obtain the total score :

[0034] ;

[0035] Set threshold If Then it means that there is a mutation in the alignment sequence, for each position with a negative score, mark it as a mutation position, and send the total score of the alignment sequence And the mutation position to the user interface.

[0036] Compared with the prior art, the beneficial effects of the present application are:

[0037] In the detection and screening system of umbilical cord blood stem cells, the collection and processing unit obtains umbilical cord blood stem cells by collecting, sub-packaging, sampling and pretreating the umbilical cord blood contained in the umbilical cord, which is beneficial to maintain the activity and function of the cells, the detection and analysis unit simultaneously sequences the gene fragments by high-throughput sequencing technology, which improves the detection efficiency, quickly determines the sequencing depth and coverage of the gene fragments, improves the accuracy of detection, reduces the false negative rate, ensures that more comprehensive genomic regions are analyzed, the judgment output unit automatically analyzes the gene fragments of the umbilical cord blood stem cells according to the sequencing depth and coverage, judges whether the gene fragments of the umbilical cord blood stem cells appear mutations, can quickly process a large amount of data, significantly shortens the analysis period, more accurately identifies potential mutation regions, and reduces the risk of missed detection. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is the overall block diagram of the present application.

[0039] The meanings of various labels in the figure are:

[0040] 1, collection processing unit; 2, detection analysis unit; 3, judgment output unit. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0042] Embodiment 1: The present application provides a detection and screening system for umbilical cord blood stem cells, please refer to Figure 1 As shown, including collection processing unit 1, detection analysis unit 2, judgment output unit 3;

[0043] The collection processing unit 1 is used for collecting, sub-packaging and sampling the umbilical cord blood contained in the umbilical cord, obtaining the umbilical cord blood sample, and pre-treating the umbilical cord blood sample through automatic processing to obtain the umbilical cord blood stem cells;

[0044] The collection processing unit 1 uses a four-bag blood collection bag to collect the neonatal umbilical cord blood in a closed manner, stores the collected umbilical cord blood according to different detection items, extracts samples from the sub-packaged umbilical cord blood, and pre-treats the umbilical cord blood sample through automatic processing to obtain the umbilical cord blood stem cells;

[0045] The umbilical cord blood sample is placed into a cell separator based on the principle of centrifugation, and after starting centrifugation, the speed is first started at 500 rpm for two minutes to make the sample gradually adapt to the centrifugal force, and then gradually increased to 1800 rpm for ten minutes to promote the effective stratification of different components in the umbilical cord blood. After the main centrifugation stage is completed, the speed is decreased by 200 rpm per minute until it stops to avoid damage to the cells due to sudden stopping. The intermediate layer cell suspension of the stem cells is automatically collected, and the separated cell suspension is transferred to a cell purification kit. The reagents in the kit interact with the cells, specifically bind to non-stem cell components, remove the combined impurities by filtration, and leave the pure umbilical cord blood stem cells.

[0046] The umbilical cord blood sample is placed into a cell separator based on the principle of centrifugation, and after starting centrifugation, the speed is first started at 500 rpm for two minutes to make the sample gradually adapt to the centrifugal force, and then gradually increased to 1800 rpm for ten minutes to promote the effective stratification of different components in the umbilical cord blood. After the main centrifugation stage is completed, the speed is decreased by 200 rpm per minute until it stops to avoid damage to the cells due to sudden stopping. The intermediate layer cell suspension of the stem cells is automatically collected, and the separated cell suspension is transferred to a cell purification kit. The reagents in the kit interact with the cells, specifically bind to non-stem cell components, remove the combined impurities by filtration, and leave the pure umbilical cord blood stem cells.

[0047] The detection analysis unit 2 introduces high-throughput sequencing technology to divide the gene fragments of the umbilical cord blood stem cells into multiple segments of equal length, and simultaneously sequences the multiple segments of the gene fragments of the umbilical cord blood stem cells to determine the sequencing depth and coverage of the gene fragments of the umbilical cord blood stem cells;

[0048] The detection analysis unit 2 introduces high-throughput sequencing technology to sequence the gene fragments of the umbilical cord blood stem cells, determines the sequencing depth and coverage of the gene fragments of the umbilical cord blood stem cells, and specifically includes:

[0049] High-throughput sequencers generally require specific library formats and fragment sizes for effective sequencing. Library construction fragments nucleic acids to appropriate lengths and adds necessary adapters and primer binding sites to make them compatible with sequencing platforms;

[0050] Nucleic acids are extracted from umbilical cord blood stem cells, long-chain nucleic acids extracted are randomly cut into fragments of k base pairs in length using ultrasonic fragmentation, and the ends of the fragmented nucleic acids are smoothed using enzymes, and then a phosphate group is added to make the end structure complete. After repairing the nucleic acid fragments, oligonucleotide adapters are connected to both ends of the nucleic acid fragments, and the oligonucleotide adapters contain primer binding sites and index sequences required for sequencing. The library construction is completed, and the constructed library is loaded onto a high-throughput sequencer for sequencing to obtain the total sequencing base number of the umbilical cord blood stem cells. The genome size is determined according to the total sequencing base number of the umbilical cord blood stem cells, and the sequencing depth and coverage are calculated from the total sequencing base number and the genome size of the umbilical cord blood stem cells. The calculation of the sequencing depth and coverage, and the specific calculation formula of the genome size is:

[0051] ;

[0052] Wherein, represents the genome size, represents the frequency of k-mers of a specific length statistically obtained from sequencing data, represents the total sequencing base number, is a correction factor, and k-mer refers to a subsequence of length base pairs taken continuously from a nucleic acid sequence;

[0053] The calculation of the sequencing depth and coverage specifically includes:

[0054] Sequencing depth is used to increase the sensitivity of detection. By increasing the sequencing depth, i.e. sequencing a certain site more times, the probability of detecting low-frequency mutations can be increased. Even if the proportion of mutations in the sample is very small, sufficient sequencing depth can provide more opportunities to discover these rare mutation events. Coverage indicates that the genome is fully covered, so that most regions of the genome can be sequenced. The sequencing depth and coverage are calculated from the total sequencing base number and the genome size of the umbilical cord blood stem cells. The calculation formula of the sequencing depth is:

[0055] ;

[0056] Wherein, Sequencing depth, Total sequencing bases, Genome size, the formula for calculating coverage is:

[0057] ;

[0058] Wherein, Coverage, k represents the number of sequencing reads.

[0059] The determination output unit 3 automatically analyzes the gene fragments of the umbilical cord blood stem cells according to the sequencing depth and the coverage, obtains a comparison quality score, and determines whether the gene fragments of the umbilical cord blood stem cells have mutations according to the comparison quality score, and uploads the determination result to the user interface;

[0060] The determination output unit automatically analyzes the sequencing depth and the coverage of the gene fragments of the umbilical cord blood stem cells to obtain a comparison quality score, specifically including:

[0061] The base quality value is extracted from the gene fragments of the umbilical cord blood stem cells, and the formula for calculating the base quality value is:

[0062] ;

[0063] Wherein, The probability that the base is read incorrectly during sequencing is represented as the base quality threshold value, the read with a quality value lower than the threshold value is deleted, the adapter sequence at both ends of the sequencing read is identified and cut off, and the same read that appears repeatedly is deleted to reduce the deviation of subsequent analysis, and the comparison sequence is obtained. The comparison algorithm is used to compare the comparison sequence with the standard genome, the standard genome is extracted from the gene library, the position of the read on the reference genome and the comparison quality score are recorded, the position is represented by the coordinates on the genome, for example, the chromosome number and the start and end base positions on the chromosome. By recording these positions, we can know the relative position of the sequencing read in the whole genome, for example, if a read matches the region from the 1000th base to the 1500th base on the 1st chromosome of the reference genome, the recorded position information is "chr1: 1000-1500". The comparison quality score is a numerical index for evaluating the matching quality of the read and the reference genome, and different scores are assigned to matching, mismatching, insertion and deletion, etc. to calculate:

[0064] Example: suppose the matching score is +1, the mismatching score is -1, and the insertion and deletion score is -2, and the reference sequence is: ATGCG, the sequencing read: ATGCA, then the comparison quality score is:

[0065] ;

[0066] in, To compare quality scores, This is represented as a match. This is a mismatch.

[0067] The output unit determines whether gene fragments in umbilical cord blood stem cells have mutated based on the alignment quality score, specifically including:

[0068] Sequencing data of umbilical cord blood stem cells were acquired, preprocessed, and aligned to obtain the alignment quality score of each read on the reference genome. By analyzing the alignment quality scores of a large number of known normal umbilical cord blood stem cell samples, a threshold was determined. For the umbilical cord blood stem cell gene fragment to be detected, the statistical value of the alignment quality scores of all reads contained therein was calculated. If the statistical value of the alignment quality score of the gene fragment is lower than the set threshold, the gene fragment is determined to have a mutation.

[0069] If the alignment quality score of a gene fragment is lower than a set threshold, the gene fragment is determined to have a mutation, specifically including:

[0070] The standard genome sequence was defined as The alignment sequence is defined as Define a fractional function Indicates the first sequence in the alignment sequence The quality score of each position is calculated for each gene fragment position i, using the standard genome sequence. and alignment sequence Matching score :

[0071] ;

[0072] For insertions and missing values, define an insertion penalty. and missing punishment If a new base is inserted at position i in the sequencing sequence, the insertion penalty score is set to 1. ,but ,otherwise If a base is missing at position i in the sequencing sequence, the deletion penalty score is set to 1. ,but ,otherwise The score at position i is obtained by combining the matching score, insertion penalty, and missing penalty. :

[0073] ;

[0074] The total score is obtained by comparing and scoring all positions in the sequence. :

[0075] ;

[0076] Setting threshold , if , it is indicated that there is a mutation in the compared sequence, for each position with a negative score, mark it as a mutation position, and send the total score of the compared sequence and the mutation position to the user interface.

[0077] In the application, the collection and processing unit obtains umbilical cord blood stem cells by collecting, sub-packaging, sampling and pretreating the umbilical cord blood contained in the umbilical cord, which is conducive to maintaining the activity and function of the cells. The detection and analysis unit simultaneously sequences the gene fragments through high-throughput sequencing technology, improves the detection efficiency, quickly determines the sequencing depth and coverage of the gene fragments, improves the accuracy of detection, reduces the false negative rate, ensures that more comprehensive genomic regions are analyzed, the judgment output unit automatically analyzes the gene fragments of the umbilical cord blood stem cells according to the sequencing depth and coverage, judges whether the gene fragments of the umbilical cord blood stem cells appear mutations, can quickly process a large amount of data, significantly shortens the analysis period, more accurately identifies potential mutation regions, and reduces the risk of missed detection.

[0078] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above examples, the above examples and descriptions in the specification are only preferred examples of the present application, and are not intended to limit the present application, various changes and improvements can be made to the present application without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A system for detection and screening of umbilical cord blood stem cells, comprising, It comprises a collection processing unit (1), a detection analysis unit (2), and a judgment output unit (3). The collection processing unit (1) is used for collecting, sub-packaging, and sampling the umbilical cord blood contained in the umbilical cord to obtain an umbilical cord blood sample, and pre-processing the umbilical cord blood sample through automatic processing to obtain umbilical cord blood stem cells. The umbilical cord blood sample collected is placed in a cell separation machine based on the centrifugal principle, and after starting centrifugation, the centrifugal speed is first started at 500 rpm for two minutes, then gradually increased to 1800 rpm for ten minutes, and then gradually decreased at a speed of 200 rpm per minute until stopped, and the intermediate layer cell suspension of the stem cells is automatically collected. The cell suspension obtained by separation is transferred to a cell purification kit, and the reagents in the kit interact with the cells to specifically bind non-stem cell components, remove the bound impurities by filtration, and leave the pure umbilical cord blood stem cells. The detection analysis unit (2) introduces high-throughput sequencing technology to divide the gene fragments of the umbilical cord blood stem cells into multiple segments of equal length, and simultaneously sequences the multiple gene fragments of the umbilical cord blood stem cells to determine the sequencing depth and coverage of the gene fragments of the umbilical cord blood stem cells. The detection analysis unit (2) introduces high-throughput sequencing technology to sequence the gene fragments of the umbilical cord blood stem cells to determine the sequencing depth and coverage of the gene fragments of the umbilical cord blood stem cells, which specifically includes: Nucleic acids are extracted from the umbilical cord blood stem cells, the extracted long-chain nucleic acids are randomly cut into fragments of k base pairs in length using ultrasonic crushing, and the ends of the fragmented nucleic acids are smoothed using enzymes, then a phosphate group is added, and oligonucleotide adapters are connected to the ends of the repaired nucleic acid fragments to complete library construction. ； wherein, is expressed as genome size, is expressed as a specific length of k-mer by sequencing data statistics, is expressed as total number of sequencing bases, is a correction factor, and the k-mer refers to a subsequence of length of bases taken contiguously from a nucleic acid sequence; The sequencing depth and coverage are calculated from the total sequencing base number of the umbilical cord blood stem cells and the genome size, and the calculation of the sequencing depth and coverage specifically includes: The sequencing depth and coverage are calculated from the total sequencing base number of the umbilical cord blood stem cells and the genome size, and the calculation formula of the sequencing depth is: ； wherein, is expressed as sequencing depth, is expressed as total number of sequenced bases, is expressed as genome size, and the formula for calculating the coverage is: ； wherein, expressed as coverage, expressed as number of sequencing reads; The judgment output unit (3) automatically analyzes the gene fragments of the umbilical cord blood stem cells according to the sequencing depth and coverage, obtains a comparison quality score, and judges whether mutations occur in the gene fragments of the umbilical cord blood stem cells according to the comparison quality score, and uploads the judgment result to a user interface. The judgment output unit (3) automatically analyzes the sequencing depth and coverage of the gene fragments of the umbilical cord blood stem cells to obtain a comparison quality score, which specifically includes: The base quality value is extracted from the gene fragments of the umbilical cord blood stem cells, and the calculation formula of the base quality value is: ； wherein, The probability of the base being read incorrectly during sequencing is represented as a base quality score. The average base quality score is set as a base quality threshold. The reads with a quality score lower than the threshold are deleted. The adapter sequences at both ends of the sequencing reads are identified and cut off. The same reads that appear repeatedly are deleted. The aligned sequences are obtained. An alignment algorithm is used to align the aligned sequences with a standard genome, which is extracted from a gene library. The position of the reads on the reference genome and the alignment quality score are recorded. The position is represented by coordinates on the genome. The alignment quality score is a numerical indicator for evaluating the alignment result of the reads with the reference genome. The judgment output unit (3) judges whether mutations occur in the gene fragments of the umbilical cord blood stem cells according to the comparison quality score, which specifically includes: The sequencing data of the umbilical cord blood stem cells are acquired, preprocessed and aligned to obtain alignment quality scores of each read on a reference genome, a threshold is determined by analyzing the alignment quality scores of a large number of known normal umbilical cord blood stem cell samples, and for a gene fragment of the umbilical cord blood stem cells to be detected, statistical quantities of the alignment quality scores of all reads contained in the gene fragment are calculated, and if the statistical quantity of the alignment quality scores of the gene fragment is lower than the set threshold, it is determined that the gene fragment has a mutation.

2. The system for detection and screening of umbilical cord blood stem cells as claimed in claim 1 wherein: The collection processing unit (1) uses a four-bag blood collection bag to collect the umbilical cord blood of a newborn in a closed manner, stores the collected umbilical cord blood according to different detection items, draws samples from the separated umbilical cord blood, and obtains umbilical cord blood stem cells by automatically processing the umbilical cord blood samples.

Images